(NT 6.0)

2006 Not supported
Almost never used (NT 6.1) 2009 Not supported
Actively used (NT 6.2) 2012 Not supported
Almost never used (NT 6.3) 2013 Supported
Almost never used (NT 10) 2015 Supported
Actively used

Server Windows

Logo Version Year Status
1993 Not supported
Generally not used
1994
1995
1996
2000
2003 Not supported
Still in use
2005
2008
2009 Supported
Actively used
2012
2013
2016
2018 Getting Started

All Windows versions by line + chronology

Ruler years Version enumeration
16 bit 1985 - 1995 Windows 1 / 2 / 3
32 bits
(9x)		 1995 - 2001 Windows 95/98/ME
NT
(32 and 64 bits)		 since 1993 Windows NT 3.1 / NT 3.5 / NT 3.51 / NT 4.0 Workstation / 2000 / XP / Vista / 7 / 8 / 8.1 / 10
NT Servers
(32 and 64 bits)		 since 1993 Windows NT 3.1 / NT 3.5 / NT 3.51 / NT 4.0 Server / 2000 Server / 2003 / 2003 R2 / 2008 / 2008 R2 / 2012 / 2012 R2 / 2016 / 2019

History of success

This success story reflects the frequency of use of the system; the number of glitches encountered by users; reviews.

Windows 1 Failure
Windows 2 Neutral
Windows 3 Success
Windows 95 Failure
Windows 98 Success
Windows Millennium Failure
Windows 2000 Neutral
Windows XP Big success
Windows Vista Failure
Windows 7 Success
Windows 8 Failure
Windows 8.1 Failure
Windows 10 Success

* despite the failure of some versions of the operating system, they carried new features that were transferred to already successful versions. For example, in the millennium, beautiful icons and windows appeared, which were carried over to Windows 2000. Therefore, failure should not be assessed as a failure.

Windows 1

Years of support: 1985 - 2001. Branch: 16 bits.

Editions: -

What's new

Before Windows 1, there was MS-DOS, so the most important innovation is the graphical interface and the ability to control with the mouse.

System requirements

Windows 3

Years of support: 1990 - 2008. Branch: 16 bit.

Editions: -

What's new

  • The first (from Microsoft) user-friendly interface.
  • The appearance of the program manager.
  • The emergence of multimedia capabilities.
  • Network support (since 3.1).

System requirements

Windows NT 3.1

Editions: -

What's new

  • The first system based on the NT kernel.
  • Support file system NTFS.

System requirements

CPU Intel 80386
RAM 2 MB
Hard disk capacity 8 MB

Windows NT 3.5 Workstation

Editions: -

What's new

  • Built-in Winsock and TCP/IP support.
  • The advent of DHCP and WINS server and client.
  • VFAT support.

System requirements

CPU 33 MHz
RAM 12 MB
Hard disk capacity 70 MB

Windows NT 3.51 Workstation

Editions: -

System requirements

Windows NT 4.0 Workstation

Editions: -

System requirements

Windows 98

Years of support: 1998 - 2006. Branch: 9x (32 bits).

System requirements

Windows Millennium

Years of support: 2000 - 2006. Branch: 9x (32 bits).

System requirements

Windows 2000

Years of support: 2000 - 2010. Branch: NT.

System requirements

Windows XP

Editions: XP, XP Professional

System requirements

Windows Vista

Years of support: 2006 - 2017. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Starter, Basic Home, Premium Home, Business, Enterprise, Ultimate

System requirements

Windows 7

Years of support: 2009 - 2020. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Starter, Home Basic, Home Premium, Professional, Enterprise, Ultimate

System requirements

Minimum Featured
Architecture 32-bit 64-bit 32-bit 64-bit
CPU 1 GHz
RAM 1 GB 2 GB 4 GB
Hard disk capacity 16 GB 20 GB 16 GB 20 GB

Windows 8

Years of support: 2012 - 2016. Branch: NT. Bit depth: 32 and 64 bits.

System requirements

Minimum Featured
Architecture 32-bit 64-bit 32-bit 64-bit
CPU 1 GHz
RAM 1 GB 2 GB 4 GB
Hard disk capacity 16 GB 20 GB 16 GB 20 GB

Windows 8.1

Years of support: 2013 - 2023. Branch: NT. Bit depth: 32 and 64 bits.

Editions: 8, 8 Professional (Pro), 8 Corporate (Enterprise)

System requirements

Minimum Featured
Architecture 32-bit 64-bit 32-bit 64-bit
CPU 1 GHz
RAM 1 GB 2 GB 4 GB
Hard disk capacity 16 GB 20 GB 16 GB 20 GB

Windows 10 (latest for personal computers)

Years of support: 2015 - 2025. Branch: NT. Bit depth: 32 and 64 bits.

Editions

  • Home (Home). For most home computers. There is no way to set up a remote desktop so that the system can be connected remotely; not possible to use group policies and joining a domain.
  • Professional (Pro). Contains all the features of the home version + the ability to join a domain, use group policies, the ability to connect to a computer using remote desktop.
  • Corporate (Enterprise). Some features of the home version have been cut. There are all the additional features of the Pro + DirectAccess version, AppLocker.
  • S. Is a stripped down version; preinstalled on some devices. Do not support standard installation Applications - Can only be installed from the Windows Store.

What's new

Windows 10 is undergoing major changes with the release of new builds. Therefore, we will consider innovations on the basis of this.

  • Improved performance.
  • New built-in browser Microsoft Edge.
  • Automatic shrinking of an adjacent window when the active window is pressed to one side of the desktop.
  • "All apps" in "Start" supports displaying 2048 items (previously only 512).
  • Forced installation of updates.
  • Using virtual voice assistant Cortana.
  • The updated start menu is a hybrid of previous versions and Windows 8 (the old version of the disclosure returned, and tiles appeared on the right side).
  • Ability to create multiple desktops.
  • Rejection of the Windows 8 tiled system.
  • Handwriting capability (Windows Ink).
  • Webcam identification.
  • Synchronization with mobile device notifications.
  • Changing the system options menu.
  • Built-in support for virtual reality helmets.
  • Game Mode
  • Suggested by default command line in powershell.
  • Access to the Classic Control Panel is hidden from the context menu. Now it can be called with the command control.
  • Improvement of the built-in antivirus.
  • Webcam authentication for Active Directory.
  • The ability to create a screenshot with a selection of an area using the keyboard shortcut Win + Shaft + S.
  • Braille support.
  • Extended battery life.
  • The ability to run Cortana on one device and stop working on another.
  • Disable the SMBv1 protocol. You can enable it manually.
  • The appearance of the "People" panel.
  • GPU information in task manager.
  • Fullscreen Microsoft Edge
  • Extended battery life (Power Throttling).
  • The appearance of the emoji panel.
  • Selective OneDrive sync.
  • Fix for stuttering issues in games.
  • Possibility to recover the password using security questions.
  • Dark theme for File Explorer.
  • Possibility of accessing messages from the phone (“Your phone” function).
  • Isolated desktop for secure application launch.

* this list contains some of the innovations. Full list on the Wikipedia page.

System requirements

Minimum Featured
Architecture 32-bit 64-bit 32-bit 64-bit
CPU 1 GHz
RAM 1 GB 2 GB 4 GB
Hard disk capacity 16 GB 20 GB 16 GB 20 GB

Windows NT 3.1 Advanced Server

Years of support: 1993 - 2001. Branch: NT. Bit depth: 16, 32 and 64 bits.

Editions: -

System requirements

CPU Intel 80386
RAM 2 MB
Hard disk capacity 8 MB

Windows NT 3.5 Server

Years of support: 1994 - 2001. Branch: NT. Bit depth: 16, 32 and 64 bits.

Editions: -

What's new

  • Built-in Winsock and TCP/IP support.
  • The advent of DHCP and WINS servers.
  • Sharing files and printers.
  • VFAT support.

System requirements

CPU 33 MHz
RAM 16 MB
Hard disk capacity 70 MB

Windows NT 3.51 Server

Years of support: 1995 - 2001. Branch: NT. Bit depth: 16, 32 and 64 bits.

Editions: -

System requirements

CPU 33 MHz
RAM 16 MB
Hard disk capacity 70 MB

Windows NT 4.0 Server

Years of support: 1996 - 2004. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Server, Enterprise Edition, Terminal Server

System requirements

Windows 2000 Server

Years of support: 2000 - 2010. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Server, Advanced Server and Datacenter Server

System requirements

Windows Server 2003

Years of support: 2003 - 2015. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Web, Standard, Enterprise, Datacenter

System requirements

Web, Standard, Enterprise:

Data Center Edition:

Windows Server 2003 R2

Years of support: 2005 - 2015. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Standard, Enterprise, Datacenter

System requirements

Standard, Enterprise:

Data Center Edition:

Windows Server 2008

Years of support: 2008 - 2020. Branch: NT. Bit depth: 32 and 64 bits.

Editions: Web, Standard, Enterprise, Datacenter, HPC, Storage, Itanium

System requirements

Minimum Featured
Architecture 32-bit 64-bit 32-bit 64-bit
CPU 1 GHz 1.4GHz 2 GHz
RAM 512 MB 2 GB
Hard disk capacity 10 GB 40 GB

Windows Server 2008 R2

Years of support: 2009 - 2020. Branch: NT. Bit depth: 64 bits.

Editions: Foundation, Small Business, Web, Standard, Enterprise, Datacenter, HPC, Itanium

System requirements

Windows Server 2012

Years of support: 2012 - 2023. Branch: NT. Bit depth: 64 bits.

System requirements

Windows Server 2012 R2

Years of support: 2013 - 2023. Branch: NT. Bit depth: 64 bits.

Editions: Foundation, Essentials, Standard, Datacenter

System requirements

Windows Server 2016

Years of support: 2016 - 2026. Branch: NT. Bit depth: 64 bits.

Editions: Essentials, Standard, Datacenter

What's new

  • Licensing for physical processor cores (minimum 16).
  • New installation mode - Nano .
  • The advent of container virtualization.
  • OpenGL and OpenCL for RDP.
  • Encryption virtual machines and internal network traffic.
  • Block replication of file storages.

System requirements

Windows Server 2019 (latest for servers)

Years of support: 2018 - ?. Branch: NT. Bit depth: 64 bits.

Editions: Standard, Datacenter

What's new

  • Enhanced Security - Built-in Defender ATP and Defender Exploit Guard technologies.
  • Windows Subsystem Linux (WSL) - Containers for supporting Linux applications.
  • To build a cluster with an even number of nodes, a USB drive can be used as a witness disk.

WindowsNT

Windows NT is a line of operating systems (OS) produced by Microsoft Corporation and the name of the first versions of the OS.

Windows NT was developed after the termination of cooperation between Microsoft and IBM on OS / 2, developed separately from other operating systems of the Windows family (Windows 3.x and Windows 9x) and, unlike them, was positioned as a reliable solution for workstations (Windows NT Workstation) and servers (Windows NT Server). Windows NT gave rise to a family of operating systems that includes: Windows NT proper, Windows 2000, Windows XP, Windows Server 2003, Windows Vista, Windows Server 2008, Windows 7, Windows Server 2008 R2, Windows 8, Windows Server 2012

Architectural modulesWindowsNT

The architecture of Windows NT is modular and consists of two main layers - user-mode components and kernel-mode components. Programs and subsystems running in user mode have restrictions on access to system resources. Kernel mode has unlimited access to system memory and external devices. The kernel of an NT system is called a hybrid kernel or a macrokernel. The architecture includes the kernel itself, the hardware abstraction layer (HAL), drivers, and a number of services (Executives) that operate in kernel mode (Kernel-mode drivers) or in user mode (User-mode drivers).

Custom windows mode NT consists of subsystems that pass I/O requests to the appropriate kernel-mode driver via an I/O manager. There are two subsystems at the user level: the environment subsystem (runs applications written for different operating systems) and the integrated subsystem (manages special system functions on behalf of the environment subsystem). Kernel mode has full access to the computer's hardware and system resources. And also prevents access to critical areas of the system by user services and applications.

Differences between Windows 2000 and NT 4.0

Some of the most significant improvements in Windows 2000 over Windows NT 4.0 are:

Support for the Active Directory directory service. The Active Directory back end comes with the Server, Advanced Server, and Datacenter Server editions, while the Professional edition provides full support for the client-side service.

IIS version 5.0. Compared to IIS 4.0, this version includes, among other things, version 3.0 of the ASP web programming system.

File system NTFS version 3.0 (also called NTFS 5.0 internally in Windows 2000 - NT 5.0). This version of NTFS for the first time introduced support for quotas, that is, restrictions on the maximum amount of stored files for each user.

Updated user interface including Active Desktop based on Internet Explorer version 5 and thus similar to the interface of Windows 98. The color scheme has been redesigned.

Language integration: Previous versions of Windows were released in three versions - for European languages ​​(single-byte characters, writing only from left to right), for Far Eastern languages ​​(multi-byte characters) and for Middle Eastern languages ​​(writing from right to left with contextual letter variants). Windows 2000 combines these features; all its localized versions are made on a single basis.

Encrypted file system EFS, with which you can encrypt files and folders.

Key FeaturesWindowsXP

The Microsoft Windows XP operating system is based on NT technology and is a direct successor to Windows 2000. However, all the best innovations included in Windows Me can be found in Windows XP. While maintaining high levels of reliability, security and performance, the system has become easier to learn, it has a lot of tools designed for individual home users.

The system is supplied in several versions, oriented to different application features. Microsoft Windows XP Home Edition is designed for individual users who most often work on home computer. In this version, special emphasis is placed on working with pictures, audio and video. The version of Microsoft Windows XP Professional is intended, as the name implies, for professionals. This version is most commonly used in organizations. If you are doing complex work at home creating and editing images, modeling and construction, or any other complex work, then this version is also suitable for your home computer. The version of Microsoft Windows XP Server is designed to be installed on a server - a powerful computer that allows many users to work on a computer network. Working on local networks is outside the scope of this book, so the server version will not be considered here. The book describes the main version of the operating system - Windows XP Professional. Virtually no different version of Windows XP Home Edition. Minor differences will be highlighted.

It should be noted that in order to work effectively with the Windows XP operating system, a sufficiently powerful modern computer is required. First of all, the computer must have at least 128 megabytes of memory installed. It is better to install 256 megabytes so that the system runs faster. Any processor can be used, but not too old. If the processor clock speed is at least 300 megahertz, then it will do. Although it is better, of course, to use a processor with a frequency of more than one gigahertz. The hard drive must not only contain operating system files and temporary files, but also have enough free space, for example, to create an image of a CD before burning it. Really requires a disk size of at least two to three gigabytes. And if you consider that you need to install other programs on the disk and leave space for various documents, then a 10 gigabyte disk cannot be called too large.

The appearance of the system has changed a lot in the version of Windows XP. Buttons, icons, panels now look a little different. Even the Windows main menu has changed. The interface changes are the most significant since moving from Windows 3.1 to Windows 95. However, you can still use the old interface if you're used to it. Of particular note is the operation of programs in compatibility mode with previous versions of Windows. You can work with a program that was written for Windows 95 and does not work on Windows 2000. All versions of Windows XP have many new features. A much wider variety of devices are supported. The system allows you to easily and conveniently process videos, photos, pictures, music and songs. Now, with Windows XP, anyone can build a home network based on two or three computers, sharing files, folders, printer, fax, and Internet access.

When working with Windows XP, you do not need to install additional programs to write information to recordable and rewritable CDs. You can burn a CD directly from Windows Explorer. By the way, the conductor has changed a lot. In addition to supporting compressed folders, special folders for storing pictures, music and videos, a panel with commands has been added, the composition of which changes depending on the actions you perform.

A useful component of the system is the video editor. Now you can perform professional non-linear editing of your amateur films. It has become much easier to work with digital cameras and scanners. You do not need any additional program to enter a photo into a computer, slightly convert it and print it on a printer. The universal audio and video player now supports more formats and allows you to change its appearance. You can create yourself sound files in the popular MP3 format. The media player also supports the playback of digital video discs (DVDs), allowing you to enjoy the highest quality picture and sound of today's movies. For entertainment, Windows XP includes several new games, some of which allow you to play online.

System protection has also been significantly improved. Now, if important system files are accidentally deleted, they will be automatically restored. It is possible to restore the system to an earlier state after installing new software and hardware. Improved support for Plug & Play technology allows you to connect many modern household appliances to your computer.

The means for working with the Internet have also been further developed. The help system has been significantly redesigned, the security system has been improved. Numerous changes have affected the means of administration and management of the work of many users in a local area network.

There are many other innovations in the system, which you will learn about as you read the book and get to know Windows XP. However, before you start working with the system, we recommend that you familiarize yourself with the basic concepts used in Windows XP. If you are familiar with previous versions of Windows, most of the concepts will be familiar to you.

WindowsVista

Windows Vista is an operating system of the Microsoft Windows NT family, a line of operating systems used on consumer personal computers. At the development stage, this operating system was codenamed "Longhorn".

In the Windows NT product line, Windows Vista is version number 6.0 (Windows 2000 is 5.0, Windows XP is 5.1, Windows Server 2003 is 5.2). The abbreviation "WinVI" is sometimes used to refer to "Windows Vista", which combines the name "Vista" and the version number written in Roman numerals.

Windows Vista, like Windows XP, is exclusively a client system. Microsoft also released a server version of Windows Vista, Windows Server 2008.

On November 30, 2006, Microsoft officially released Windows Vista and Office 2007 to corporate customers. On January 30, 2007, sales of the system began in the CIS for ordinary users.

According to web analytics from W3Schools, as of October 2012, Windows Vista's market share is ▼ 3.0%; this value peaked at 18.6% in October 2009.

Windows 7

Windows 7 is the operating system of the Windows NT family, following Windows Vista. The next system in the Windows 8 line after Windows 7. In the Windows NT line, the system has version number 6.1 (Windows 2000 - 5.0, Windows XP - 5.1, Windows Server 2003 - 5.2, Windows Vista and Windows Server 2008 - 6.0). The server version is Windows Server 2008 R2, the version for integrated systems (built from Windows components) is Windows Embedded Standard 2011 (Quebec), the mobile version is Windows Embedded Compact 2011 (Chelan, Windows CE 7.0).

The operating system went on sale on October 22, 2009, less than three years after the release of the previous operating system, Windows Vista. Volume Licensing partners and customers were granted access to RTM on July 24, 2009. On the Internet, the original installation images of the final version of the system have been available since July 21, 2009.

According to web analytics from W3Schools, as of October 2012, Windows 7's share of the world's Internet operating systems was ▲ 56.8%. According to this criterion, it is in first place, surpassing the previous leader in August 2011 - Windows XP.

File systemNTFS

NTFS (from the English New Technology File System - “new technology file system”) is a standard file system for the Microsoft Windows NT family of operating systems.

The HPFS file system was first used for the OS/2 1.2 operating system to provide access to the large disks that were on the market at the time. In addition, there is a need to expand the existing naming system, improve organization and security to meet the growing needs of the network server market. The HPFS file system supports the FAT directory structure and adds sorting of files by name. The file name can contain up to 254 double-byte characters. A file is made up of "data" and special attributes, which creates additional opportunities to support other types of filenames and improve security. In addition, the smallest block for data storage is now equal to the size of the physical sector (512 bytes), which helps to reduce wasted disk space.

NTFS replaced that used in MS-DOS and Microsoft Windows file FAT system. NTFS maintains a metadata system and uses specialized data structures to store information about files to improve performance, reliability, and disk space efficiency. NTFS stores information about files in the Master File Table (MFT). NTFS has built-in capabilities to restrict access to data for different users and user groups (access control lists - Access Control Lists (ACL)), as well as assign quotas (restrictions on the maximum amount of disk space occupied by certain users). NTFS uses the USN journaling system to improve file system reliability.

NTFS is based on the HPFS (High Performance File System) file system developed by Microsoft and IBM for the OS/2 operating system. But, having received such undoubtedly useful innovations as quoting, journaling, access control and auditing, it has largely lost [source not specified 242 days] the very high performance of file operations inherent in its ancestor (HPFS).

There are several versions of NTFS: v1.2 is used in Windows NT 3.51 and Windows NT 4.0, v3.0 comes with Windows 2000, v3.1 comes with Windows XP, Windows Server 2003, Windows Server 2003 R2, Windows Vista, Windows 7 and Windows Server 2008, Windows Server 2008 R2.

The file system specifications are closed. This creates certain difficulties when implementing its support in third-party products that do not belong to Microsoft - in particular, developers of drivers for free operating systems have to reverse engineer the system.

Entries in the directory of the HPFS file system contain more information than in FAT. Along with file attributes, information about creation and modification, as well as the date and time of access, is stored here. The entries in the HPFS directory do not point to the first cluster of the file, but to the FNODE. FNODE can contain file data, pointers to file data, or other structures pointing to file data. HPFS tries to place file data in contiguous sectors whenever possible. This leads to an increase in the speed of sequential processing of the file. HPFS divides the disk into blocks of 8 MB each and always tries to write the file within the same block. For each block, 2 KB is reserved for the allocation table, which contains information about the written and free sectors within the block. Blocking leads to better performance, since the disk head to determine where to save the file must return not to the logical beginning of the disk (usually this is cylinder zero), but to the allocation table of the nearest block. In addition, the HPFS file system contains two unique data objects.

The Windows NT or New Technology operating system was created by a group of developers led by Dave Cutler.

Windows NT is a 32-bit operating system with preemptive multitasking. As fundamental components, the operating system includes security tools and a developed network service. Windows NT also provides compatibility with many other operating systems, file systems, and networks. Windows NT is able to function both on computers equipped with CISC - processors with a complex instruction set (complex instruction set computing), and on computers with RISC - processors with a reduced instruction set (reduced instruction set computing). The Windows NT operating system also supports high performance multiprocessor systems.

Familiar in Windows NT is only the appearance. Behind the graphical user interface lie powerful new features.

Tasks set when creating WindowsNT. Windows NT is not a further development of pre-existing products. Its architecture was created anew, taking into account the requirements for a modern operating system. The features of the system developed on the basis of these requirements are as follows.

In an effort to provide compatibility new operating system, the developers of Windows NT retained the familiar Windows interface and implemented support for existing file systems (such as FAT) and various applications(written for MS-DOS, OS/2 1.x, Windows 3.x and POSIX). The developers also included tools for working with various networking tools in Windows NT.

Achieved portability(portability) system that can now run on both CISC and RISC processors. CISC includes Intel-compatible processors 80386 and higher. RISCs are represented by systems with MIPS R4000, Digital Alpha AXP and Pentium P54 and higher processors.

Scalability(scalability) means that Windows NT is not tied to a single-processor computer architecture, but is able to take full advantage of the opportunities provided by symmetrical multiprocessor systems. Currently, Windows NT can run on computers with processors ranging from 1 to 32. In addition, as user tasks become more complex and the demands on the computing environment expand, Windows NT makes it easy to add more powerful and productive servers and workstations to the "corporate networks.

Additional benefits are provided by the use of a single development environment for both servers and workstations.


Windows NT has a uniform security system(security) that meets US government specifications and complies with B2 security standard. In a corporate environment, critical applications are provided with a completely isolated environment.

Distributed processing(distributed processing) means that Windows NT has networking capabilities built into the system. Windows NT also allows communication with various types of host computers through support for a variety of transport protocols and the use of high-level client-server facilities, including named pipes, remote procedure calls (RPCs), and Windows sockets.

Reliability and fault tolerance(reliability and robustness) are provided by architectural features that protect application programs from damage by each other and the operating system. Windows NT uses fault-tolerant structured processing special situations at all architectural levels, which includes a recoverable NTFS file system and provides protection through built-in security and advanced memory management techniques.

Capabilities localization(allocation) represent means for robots in many countries of the world in national languages, which is achieved by using the Unicod standard (developed by the international organization for standardization - ISO).

Thanks to the modular design of the system, extensibility Windows NT, which allows the flexibility to add new modules at various levels of the operating system.

The package includes a number of applications: Internet Information Server 2.0, Index Server, FrontPage, Internet Explorer, Domain Name System (DNS) Server, Proxy Server and Internet Resource Center, all Service Packs, Plus! and a number of additional utilities, including both new ones, such as Administrative Wizards or Imager, and improved versions of older programs, such as Task Manager.

The Administrative Wizard lets you automate common network management tasks and updated versions Windows NT Diagnostic, Performance Monitor programs are used for operational monitoring of the system status. The Task Manager dialog has been transformed into a powerful tool that provides a wealth of useful information, from CPU usage to the names of all active system processors.

One of the key components of Windows NT 4.0 is Internet Information Server 2.0. It is a flexible and multifunctional solution for both connecting to the Internet and creating your own private intranet. The user only needs to configure the TCP / IP protocol settings (with the DHCP service installed, the IP address is assigned automatically), start IIS and create one or more of their own Web pages. The Web documents are then available to all users on your network who have installed software that runs the TCP/IP protocol and a standard World-Wide Web browser.

There are some changes in the remote access subsystem, Remote Access Service (RAS). Now it is possible to use secure communication channels, the new Point-To-Point Tunneling Protocol (PPTP), the ability to use multiple modems to organize communication channels with remote networks.

Features of the network architecture of previous versions of Windows NT (a multi-level model of protection against unauthorized access, the specifics of the modular system design, etc.) limited it throughput when using Fast Internet networks. In version 4.0, the algorithms for caching network requests were improved, the modules of the resource sharing subsystem were optimized, the mechanism for generating interrupts was changed (during the transition to high-speed networks, this function unexpectedly became a source of problems for network operating systems). The second change that Microsoft is pointing out is the increased performance of the OS when performing graphics operations.

The combination of a powerful network OS and a graphical interface designed for unskilled users looks rather unusual. Windows NT 4.0 is not just another version of the popular operating system. It is the basis for a new generation of Internet-oriented software products.

Architectural modules of Windows NT. As shown, Windows NT is a modular (better than monolithic) operating system that consists of separate interconnected relatively simple modules.

The main modules of Windows NT are (listed in order from the lowest level of architecture to the top): the hardware abstraction layer HAL (Hardware Abstraction Layer), the kernel (Kernel), the executive system (Executive), protected subsystems (protected subsystems) and environment subsystems (environment subsystems).

virtualizes hardware interfaces, thereby making the rest of the operating system independent of specific hardware features. This approach allows for easy portability of Windows NT from one hardware platform to another.

Nucleus is the basis of the modular structure of the system and coordinates most of the basic operations of Windows NT. This component has been specifically optimized for space and performance. The kernel is responsible for scheduling the execution of threads, synchronizing the work of multiple processors, and handling hardware interrupts and exceptions.

Executing system includes a set of programming constructs of privileged mode (kernel mode), which represent the basic service of the operating system to the subsystems of the environment. The execution system consists of several components,

Rice. 2.32. Modular structure of Windows NT

each of them is designed to support a specific system service. Thus, one of the components - the Security Reference Monitor - operates in conjunction with protected subsystems and ensures the implementation of the system security model.

Environment subsystems are secure user-mode servers that run and support applications designed for different operating environments (different operating systems). Win32 and OS/2 subsystems are examples of environment subsystems.

Hardware abstraction layer(HAL) is a layer of software created by hardware manufacturers that hides (or abstracts) features that differentiate the hardware from the upper layers of the operating system. Thus, due to the filter provided by the HAL, different hardware looks similar from the point of view of the operating system; the need for special configuration of the operating system for the equipment used is removed.

When creating a hardware abstraction level, the task was to prepare procedures that would allow a single driver specific device support the operation of this device for all platforms. HAL is targeted at a large number of varieties of hardware platforms with a single processor architecture; thus, each of the hardware options does not require a separate version of the operating system.

HAL procedures are called both operating system tools (including the kernel) and device drivers. When working with device drivers, the hardware abstraction layer provides support for various I/O technologies (instead of the traditional focus on a single hardware implementation or costly adaptation to each new hardware platform).

The level of hardware abstractions also makes it possible to “hide” from other levels of the operating system the features of the hardware implementation of symmetric multiprocessor systems.

Nucleus(Kernel) works in close contact with the hardware abstraction layer. This module is primarily concerned with scheduling the processor's actions. If the computer contains several processors, the kernel synchronizes their work in order to achieve maximum system performance.

The kernel dispatches flows(threads - threads of control, which are sometimes called subtasks, branches), which are the main objects in the planned system. Threads are defined in the context of a process; a process includes an address space, a set of objects available to the process, and a set of control flows that are executed in the context of the process. Objects are resources managed by the operating system.

The kernel schedules the threads of control in such a way as to maximize the load on the system processors and ensure that threads with a higher priority are processed in the first place. There are 32 priority values ​​in total, which are grouped into two classes: real-time and variable. This approach allows you to achieve maximum efficiency of the operating system.

Subcomponents of the executive system, such as the I/O manager and the process manager, use the kernel to synchronize activities. They also interact with the kernel for higher levels of abstraction called kernel objects; some of these objects are exported within custom application program interface (API) calls.

The kernel manages two types of objects.

Dispatching objects(dispatcher objects) are characterized by a signaled state (signaled or nonsignaled) and control the dispatching and synchronization of system operations. These objects include events, mutants, mutexes, semaphores, threads, timers, semaphores, threads, and timers.

Control Objects(control objects) are used for kernel control operations, but do not affect scheduling or synchronization.

Control objects include asynchronous procedure calls, interupts, power notifies, power statuses, processes, profiles.

Executing system(Executive), which includes the kernel and the HAL hardware abstraction layer, provides a common system service that all subsystems of the environment can use. Each service group is managed by one of the individual components of the executive system:

Object Manager;

Virtual memory manager (Virtual Memory Manager);

Process Manager (Process Manager);

Means of calling local procedures (Local Procedure Call Facility);

I / O Manager;

Security Reference Monitor.

The security monitor, together with the Logon processor and secure subsystems, implements Windows NT security model.

The top level of the executive system is called System Services. Shown in fig. 2.33, a system service is an interface between the subsystems of the user mode environment and the privileged mode.

cache manager. The I/O architecture contains a single Cache Manager that performs caching for the entire I/O system. Caching is a technique used by the file system to increase efficiency.

Fig.2.33. System interface

Instead of directly writing to and reading from disk, frequently used files are temporarily stored in the cache; thus, work with these files is done in memory. Operations with data in memory are much faster than operations with data on disk.

The cache manager uses a file mapping model that is integrated with the Windows NT virtual memory manager. The cache manager provides a caching service for all file systems and network components that are managed by the I/O manager. Depending on the amount of available random access memory the cache manager can dynamically increase or decrease the size of the cache. When a process opens a File that was already in the cache, the cache manager simply copies the data from the cache into the virtual address space.

The cache manager supports services such as lazy write and lazy commit, which can drastically increase file system efficiency. The slow write process logs changes to the file structure cache for faster access. Later, when CPU usage is reduced, the cache manager writes the changes to disk. Slow-motion recording is like slow-motion recording. Instead of immediately marking the transaction as successful, the transferred information is cached and later written to the file system journal in the background.

File system drivers. In the Windows NT I/O architecture, file system drivers are managed by the I/O manager. Windows NT allows for a variety of file systems, including the existing FAT file systems. For bottom-up compatibility with MS-DOS, Windows 3.x, and OS/2 operating systems, Windows NT supports the FAT and HTFS file systems.

In addition, Windows NT also supports NTFS, a new file system designed specifically for use with Windows NT. NTFS provides a number of features, including file system recovery, support for Unicode, long filenames, and support for POSIX.

The Windows NT I/O architecture not only supports traditional file systems, but also allows the network editor and server to function as file system drivers. From the point of view of the I/O manager, there is no difference between working with a file hosted on a remote network computer and working with a file on a local hard drive. Redirectors and servers can be loaded and unloaded dynamically just like any other driver; one computer can simultaneously host a large number of redirectors and servers.

network drivers. The next type of drivers present as components in the I/O architecture are the network drivers. Windows NT includes integrated networking capabilities and support for distributed applications. Redirectors and servers function as file system drivers and run at or below the provider interface level, where NetBIOS and Windows socket reside.

Transport protocol drivers communicate with redirectors and servers through a layer called the Transport Driver Interface (TD1). Windows NT includes the following vehicles:

  • transmission control protocol/internet protocol TCP/IP, which provides the ability to work with a wide range of existing networks;
  • NBF is a descendant of the NetBIOS Extended User Interface (NetBEUI) that provides compatibility with existing LANs based on LAN Manager, LAN Server, and MS-Net;
  • Data Link Control (DLC), which provides an interface for accessing mainframes and networked printers;
  • NWLink is an IPX/SPX implementation that provides communication with No-well NetWare.

At the bottom of the network architecture is the network adapter card driver. Windows NT currently supports NDIS (Network Device Interface Specification) version 3.0 device drivers. NDIS provides a flexible communication environment between transport protocols and network adapters. NDIS 3.0 allows a single computer to have multiple NICs installed in it. In turn, each network adapter card can support multiple transport protocols to access different types of network stations.

Windows NT security model- represented by the security monitor (Security Reference Monitor), as well as two other components: the logon processor (Logon Process) and secure secure subsystems.

In a multitasking operating system such as Windows NT, applications share a number of system resources, including computer memory, I/O devices, files, and the system's processor(s). Windows NT includes a set of security features that ensure that applications cannot access these resources without proper permission.

The security monitor is responsible for enforcing the access validation and control policy of a particular local security subsystem. The security monitor provides services for confirming access to objects, checking user privileges, and generating messages for both privileged mode and user mode. The Security Monitor, like other parts of the operating system, runs in privileged mode.

The Windows NT logon process requires a security logon to authenticate a user. Each user must have a budget and must use a password to access that budget.

Before a user can access any computer resource from within Windows NT, the user must log on through the logon process in order for the security subsystem to recognize the username and password. Only after successful authentication, the security monitor performs an access validation procedure to determine the user's right to access this object.

Resource security is one feature provided by the security model. Tasks cannot access other people's resources (such as memory) except through the use of special sharing mechanisms.

Windows NT also provides controls that allow an administrator to capture user activity.

Windows NT memory management. Windows NT Workstation 3.51 is essentially a server operating system tailored for use on a workstation. This is the reason for the architecture, in which the absolute protection of applications and data takes precedence over considerations of speed and compatibility. The extreme reliability of Windows NT comes at a high system cost, so you need a fast CPU and at least 16MB of RAM to get acceptable performance. Under Windows NT, lower memory security is achieved by not being compatible with real-mode device drivers. Windows NT runs its own 32-bit NT applications, as well as most Windows 95 applications. Like Windows 95, Windows NT allows 16-bit Windows and DOS programs to run in its environment.

Windows NT's memory allocation scheme differs from that of Windows 95. Native application programs are allocated 2 GB of special address space, from the 64 KB boundary to 2 GB (the first 64 KB are completely inaccessible). Application programs are isolated from each other, although they can communicate through the Clipboard, DDE and OLE mechanisms.

At the top of each 2GB application block is code that the application program perceives as ring 3 system DLLs. These are actually just call forwarding stubs called client-side DLLs. When calling most API functions from a client-side DLL application, local procedures (Local Process Communication (LPC)) are invoked, which pass the call and its associated parameters to a completely isolated address space where the actual system code is contained. This server process checks the value of the parameters, executes the requested function, and sends the results back to the application's address space. Although the server process itself remains an application-level process, it is completely protected from and isolated from its caller.

Between the 2GB and 4GB marks are the low-level Windows NT ring 0 system components, including the kernel, thread scheduler, and virtual memory manager. The system pages in this area have supervisor privileges, which are set by the processor's physical ring protection circuits. This makes the low-level system code invisible and unwritable to application-level programs, but results in performance degradation during ring transitions. For 16-bit Windows applications, Windows NT implements Windows on Windows (WOW) sessions. Windows NT gives you the ability to run 16-bit Windows programs individually in their own memory spaces or together in a shared address space. In almost all cases, 16-bit and 32-bit Windows applications can interoperate freely using OLE (through special thunk routines, if necessary) whether they are running in a separate or shared memory. Native applications and WOW sessions run in preemptive multitasking based on the control of individual threads. Multiple 16-bit Windows applications in the same WOW session run according to the cooperative multitasking model. Windows NT can also multitask multiple DOS sessions. Since Windows NT is a fully 32-bit architecture, there are no theoretical limits on GDI and USER resources.

Key differences in Windows 2000. Windows 2000 or W2k is a Microsoft operating system (OS) based on Windows NT technology, which was reflected in the original name of the W2k project, Windows NT 5.0. Windows 2000 is a fully 32-bit OS with preemptive multitasking and improved memory management. The W2k project is based on the same principles that once made NT so successful.

w2k interface similar to Windows 98 interface with IE 5.0 installed. However, we still note some details.

The first thing that catches your eye is that the color scheme has changed. Now it resembles one of the schemes used in the KDE desktop for Linux. Another noticeable detail is the shadow under the mouse cursor, which is removed/exposed in the Control panel -> Mouse -> Pointers, with a tick on Enable pointer shadow. In addition, a new effect has been added when the menu appears, now they gradually appear out of thin air. Controlled from Desktop Properties, on the Effects tab, check Use transition effects for menu and tooltips.

The Start Menu introduced a feature familiar from Office 2000, when only the most frequently used items are shown when opening, the rest are opened by pressing the down arrow. You can control this effect in the Taskbar Properties, in the General tab, with the Use Personalized Menus checkbox (similarly, in 1E5 this option is disabled in Tools -> Internet Options -» Advanced -> Enable Personalized Favorites Menu). There are a few more items in Desktop Properties, including Hide keyboard navigation indicators until I use the Alt key. If it is selected, it removes the underline under the letters that mean Keyboard shortcut in Windows programs until the key is pressed. .

On the second tab of the Taskbar Properties, Advanced, there is a Start Menu Settings window, which allows you to add / remove lines included in the Start Menu, and expand some items. For example, if you tick the Expand Control Panel checkbox, then when you hover the mouse cursor over the Control Panel in the Start Menu, another menu will open to the right of it, in which there will be all the elements included in it. A useful feature on this tab is the Re-sort button. W2k, by default, puts folders with the latest installed programs at the very bottom of the Start Menu, folders can even be below links to files. Re-sort eliminates this injustice and arranges all folders from top to bottom in alphabetical order. However, the same effect can be achieved by right-clicking in Start Menu -> Programs and selecting Sort by name. In addition, with the right button, you can drag and drop any elements from there to any place.

Another difference that often fails people who have previously worked with NT and W9x, oddly enough, is the widespread use of Checkbox - Especially those that are just a square on a white background. So if you find yourself unable to do something, then look again at all the windows, perhaps you just did not pay attention to such a Checkbox.

task manager is one of the most powerful and convenient tools in NT for managing processes. It is called either , or by choosing from the menu that appears after right-clicking on the Taskbar. You can choose after .

Task manager consists of three tabs - Performance, Processes, Applications. Let's start with Performance. This tab shows real-time information about the processor(s) load, shows the load of physical memory, and shows how much RAM is used / free and how much is the system Swap "a. In addition, other additional information is given there, for example, Threads and Processes - the number of threads and processes currently running on the machine, Peak - the peak size of Swap "a during the session, Nonpaged - the amount of memory allocated for the kernel. This information can be used when you need to answer the question of what factor in the system is the "bottleneck" that slows down the work (although it is better to use Performance Monitor for this purpose).

The second tab, Processes, contains a list of currently active processes. For each process, you can find out some additional information, such as: PID (Process ID), the amount of RAM used, the number of threads generated by the process, and much more. You can add/remove displayed parameters via View -> Select Columns. In addition, quite specific actions can be performed with any of these processes. To do this, you just need to right-click on it, a context menu will appear, through which you can end the process, End Process, you can “kill” the process itself and all the others that it “spawned”, End Process Tree. You can set the priority of the process, from the highest RealTime to the lowest, Low. If the machine has two processors and a multiprocessor core, then another item appears in this menu, Set Affinity, which allows you to transfer the process to another processor, Cpu 0, Cpu l, and so on up to Cp31.

The last tab of the Task Manager - Applications, allows you to view a list of running applications and terminate any of them. Task Manager not only allows you to end applications, it can also start new applications. File -> New task (Run).

Active Directory- is a new user and network resource management tool. It is designed to facilitate the work of administrators of large networks based on W2k, and the entire network management and security system is built around it. To install Active Directory, you must have W2k Server. W2kPro can run in an Active Directory environment but cannot create one. Active Directory is built on the following principles:

1. Single registration in the network. Thanks to IntelliMirror technology, you can go to any computer in the office, enter your password

and in front of you will be your desktop, your documents and your settings.

2. Information security. Active Directory has built-in user authentication. For each object in the network, you can centrally set access rights, depending on groups and specific users. With Kerberos security, you can communicate securely even over open networks such as the Internet. At the same time, data transmitted over the network is encrypted, and passwords are not transmitted or stored on client machines. The Kerberos security system (named after the mythical three-headed dog, which, according to Greek mythology, guarded the gates of hell) has been known for a long time, but it is used for the first time in the OS from Microsoft. Without going into details, this system works like this:

The client sends a request to the authentication server for permission to access the required information;

The server checks the client's rights and sends him permission to receive the required information, encrypted using a key known to the client, and at the same time sends a temporary encryption key. Using this key, all transmitted information is encrypted, and the key lifetime is limited, so the authentication server sends a new key from time to time (naturally, the new key is encrypted using the current key), which is unknown to anyone except the server and client. Regularly changing encryption keys makes life very difficult for attackers who are hunting for your data.

However, as we all remember, in the Greek myth Kerberos could not resist the mighty Hercules. So in our case, despite all its advantages, the Kerberos security system cannot withstand all types of attacks. For example, it is possible to bombard an application with false requests, a so-called "Deny of service" attack, which can result in the application not using the Kerberos protocol.

3. Centralized management. When using Active Directory, the administrator does not have to manually configure each machine if, for example, it is necessary to change access rights to any one object or install a new network printer. Such changes can be made immediately For the entire network.

four . Flexible interface. Directory structures change quickly and easily. For example, you can create a catalog of your company, separate the accounting department, marketing departments, secretariat into separate subdirectories and present all this in the form of a tree structure. Or, for example, create several trees representing different offices in different buildings or regions and easily set the connection and access rights between them. Connect a network printer to the accountant's directory with a single mouse movement. (The drivers will be installed on these computers automatically.) Or drag and drop the entire accounting department from one server to another with all their rights, folders and documents.

5. Integration with DNS. Through tight integration with Active Directory DNS, the same resource names are used on the local network as on the Internet, which leads to less confusion and promotes closer interaction between the local and wide area networks.

6. Scalability. Multiple Active Directory domains can be combined together under one management.

7. Ease of searching. In an Active Directory domain, various objects can be found by a variety of attributes, such as the user or computer name, the user's email address, and so on.

DFS (Distributed File System) is one of the Active Directory tools. It allows you to create network shares, which can include many file systems on different machines. For an Active Directory user, this is absolutely transparent and does not matter where and on what machines the files he works with are physically located - for him they are all located in one place. In addition, when using DFS and Active Directory, the management of such resources is simplified. It is centralized, you can easily and painlessly add new resources or delete old ones, change the physical location of the files included in DFS, etc.

At the end of 1988, Microsoft appointed David Cutler to lead a new project in the field of software: to create a new Microsoft operating system for the 1990s. He assembled a team of engineers to develop a New Technology (NT) system.

The original plan was to develop NT with OS/2-style user and program interfaces (APIs), but OS/2 sold poorly, and Windows 3.0 was a great and ongoing success in the marketplace. Seeing the market challenge and the complexities involved in developing and maintaining two incompatible systems, Microsoft decided to change course and direct its engineers towards a strategy of a single holistic operating system. This strategy was to develop a family of Windows-based operating systems that would cover many types of computers, from the smallest laptops to the largest multiprocessor workstations. Thus, the next generation of Windows systems was called Windows NT.

Windows NT supports the graphical user interface (GUI) of Windows and is also the first Windows operating a Microsoft system that supports the Win32 API, a 32-bit programming interface for developing new applications. The Win32 API exposes advanced operating system features such as multithreading, synchronization, security, I/O, and object management to applications.

In July 1993, the first operating systems of the NT family appeared - Windows NT 3.1 and Windows NT Advanced Server 3.1.

Versions

  • Windows NT 3.1 (July 27, 1993)
  • Windows NT 3.5 (September 21, 1994)
  • Windows NT 3.51 (May 30, 1995)
  • Windows NT 4.0 (August 24, 1996)
  • Windows 2000 (February 17, 2000)
  • Windows XP (October 25, 2001)
  • Windows XP 64-bit Edition (March 28, 2003)
  • Windows Server 2003 (April 25, 2003)
  • Windows XP Media Center Edition 2003 (December 18, 2003)
  • Windows XP Media Center Edition 2005 (October 12, 2004)
  • Windows XP Professional x64 Edition (April 25, 2005)
  • Windows Fundamentals for Legacy PCs (July 8, 2006)
  • Windows Vista (November 30, 2006)
  • Windows Home Server (November 7, 2007)
  • Windows Server 2008 (February 27, 2008)

Structure of Windows NT

Structurally, Windows NT can be represented as two parts: the user mode part of the operating system and the kernel mode part of the operating system.

The part of Windows NT that runs in kernel mode is called the executive part. It includes a number of components that manage virtual memory, objects (resources), I/O and the file system (including network drivers), process communication, and part of the security system. These components interact with each other using inter-module communication. Each component invokes the others through a set of carefully specified internal procedures.

The second part of Windows NT, operating in user mode, are servers - the so-called protected subsystems. Since subsystems cannot automatically share memory, they communicate with each other by sending messages. Messages can be sent between a client and a server, or between two servers. All messages go through the Windows NT runtime. The Windows NT kernel schedules protected subsystem threads in the same way it schedules normal application process threads.

Support for protected subsystems is provided by the execution part. Its constituent parts are:

  • Object manager. Creates, deletes, and manages runtime objects, abstract data types used to represent system resources.
  • Security monitor. Sets security rules for local computer. Protects operating system resources, protects and registers executable objects.
  • Process manager. Creates and terminates, suspends and resumes processes and threads, and stores information about them.

Virtual memory manager.

  • I/O subsystem. Includes the following components:
    • an I/O manager that provides device-independent I/O;
    • file systems - NT drivers that execute file-oriented I / O requests and translate them into calls to conventional devices;
    • network redirector and network server - file system drivers that transmit remote I / O requests to network machines and receive requests from them;
    • executive device drivers - low-level drivers that directly control the device;
    • a cache manager that implements disk caching.

The execution part, in turn, is based on the lower-level services provided by the NT kernel. Kernel functions include:

  • process planning,
  • handling interrupts and exceptions,
  • processor synchronization for multiprocessor systems,
  • system recovery after failures.

The kernel runs in privileged mode and is never removed from memory. The only way to access the kernel is through an interrupt.

Windows NT protected subsystems run in user mode and are created by Windows NT at boot time. Immediately after creation, they begin an endless cycle of their execution, responding to messages coming to them from application processes and other subsystems. Among protected subsystems, one can single out a subclass called environment subsystems. Environment subsystems implement operating system application interfaces (APIs). Other types of subsystems, called integral subsystems, perform tasks required by the operating system. For example, most of the Windows NT security system is implemented as an integral subsystem, network servers are also implemented as integral subsystems.

The most important environment subsystem is Win32, a subsystem that provides application access to the 32-bit Windows API. Additionally, this system provides a graphical interface and manages user input/output.

Each protected subsystem runs in user mode, calling a system runtime service to perform privileged actions in kernel mode. Network servers can run in both user mode and kernel mode, depending on how they are designed.

Subsystems communicate with each other by passing messages. When, for example, a user application calls an API procedure, the environment subsystem that provides the procedure receives the message and executes it either by calling the kernel or by sending the message to another subsystem. When the procedure completes, the environment subsystem sends a message to the application containing the return value. Sending messages and other activities of protected subsystems is invisible to the user.

The main tool that holds all the Windows NT subsystems together is the Local Procedure Call (LPC) mechanism. LPC is an optimized version of the more general remote procedure call (RPC) that is used to communicate between clients and servers located on different machines on a network.

Based on the NT (New Technology) kernel, developed by Microsoft Corporation. The system was aimed at corporate users. Windows NT had a graphical user interface and provided the Win32 API, a 32-bit application programming interface for developing new applications that could take full advantage of high-level operating systems, such as multi-threaded (or multi-tasking) processes, synchronization, and anti-tampering. access, I/O and object management. Windows NT could communicate with other Microsoft operating systems, with the Apple Macintosh, with UNIX-like systems over networks. various types. Interaction could take place both with single-processor and multi-processor computers built using CISC or RISC technologies. Initially, Windows NT developed separately from the Windows 9x family of operating systems and was positioned on the market as a solution for workstations (Windows NT Workstation) and servers (Windows NT Server). Windows NT gave rise to a family of operating systems that includes Windows 2000, Windows XP, Windows Server 2003.

In November 1988, a joint project between IBM and Microsoft was launched to create a new generation operating system - OS / 2 NT, which could run programs written for both Windows and OS / 2, and was supposed to be a replacement for both systems. But in May 1990, Windows 3.0 was released, which brought Microsoft commercial success, and the company decided to make the Windows API the main one in OS/2 NT. This caused resentment from IBM, which promoted the OS/2 API. As a result, the contract was terminated, and the companies began to develop the existing common code on their own. IBM developed OS/2 3.0, while Microsoft developed Windows NT, which appeared in August 1993. Subsequently, she was given the number 3.1 to match the Windows 3.1 released a little earlier. The new system was distinguished from Windows 3.1 by the following features:

  • 32-bit. The new system could use all the features of 32-bit processors, including running 32-bit programs and addressing large amounts of memory (up to 4 gigabytes);
  • preemptive multitasking. The operating system did not wait for the process itself to want to release the processor, but forcibly removed it from execution after it had used up the time allotted to it;
  • lack of MS-DOS. Windows NT 3.1 was an independent operating system, had its own bootloader. When shutting down, the system did not exit to MS-DOS, but offered to turn off or restart the computer;
  • UNICODE support. It was the first operating system to support UNICODE internally;
  • multiplatform. Windows NT ran not only on 32-bit x86 processors, but also on 64-bit MIPS R4000 and DEC Alpha 21064;
  • support for 16-bit OS/2 programs. Part of the rights to the OS/2 code remained with Microsoft, so this and all subsequent versions of Windows NT could run such programs;
  • compatibility with POSIX 1.0 applications at the source code level;
  • support for symmetric multiprocessing (up to 16 processors);
  • support for file systems: native NTFS and HPFS inherited from OS/2. Both systems, unlike FAT, could use long filenames, up to 255 characters;
  • improved networking capabilities. In addition to the supported NetBEUI and IPX protocols, SMB, TCP/IP, and SNMP have been added;
  • a tree registry editor that stored all system settings.

Windows NT 3.1 had the same user interface, like Windows 3.1, and came in two editions - Windows NT and Windows NT Advanced Server. Subsequently, three service packs (Service Pack) were released for this system, and in September 1994 appeared a new version- 3.5. Compatibility with NetWare networks, support for long filenames in FAT, support for the OpenGL API, improved work of 16-bit programs for Windows and MS-DOS (each now worked in its own address space) were added. Like its predecessor, it came in two editions - Windows NT Workstation and Windows NT Server. In May 1995, Windows NT 3.51 appeared. Differences from previous version were minor: an installer with a new graphical interface, a new help system with content, and support for PowerPC processors. Three Service Packs were released for NT 3.5 and five for 3.51.

Simultaneously with the release of NT 3.51, the Shell Technology Preview package appeared, providing a new interface with the Start menu. This interface was implemented by default in Windows 95 two months later, and in August 1996 in Windows NT 4.0. In addition to the new interface, the fourth version of the system was distinguished by improved networking capabilities (included in the standard delivery of Internet Explorer 2.0, IIS and DNS server, support for multiprotocol routing), new DCOM technology and a large number of editions. In addition to Workstation and Server, in 1997 the Server Enterprise Edition was released with improved scalability and limited support for clusters, and in 1998 - Terminal Server with the ability to remotely connect users. In addition, it has been developed special version for embedded systems - Windows NT 4.0 Embedded. Service Pack 7 was released for NT 4.0, the latest version being called 6.0a.

In September 1997 and August 1998, two beta versions of the Windows NT 5.0 operating system were released, and in October 1998 it was renamed Windows 2000. The release of this system took place in February 2000. New features included: Active Directory directory service, Plug&Play and FAT32 file system support, new versions of network programs (IE 5.0 and IIS 5.0), improved encryption capabilities (including Encrypted File System support), built-in remote administration tools. Unlike NT 4.0, Windows 2000 ran only on the IA-32 architecture and came in four editions: Professional, Server, Advanced Server, and Datacenter Server. For Windows 2000, Service Pack 4 was released, and in August 2001, a 64-bit version of Advanced Server for Itanium processors appeared.

A new version of NT 5.1 appeared in October 2001 under the name Windows XP and was a development of Windows 2000 Professional. The main changes were an improved user interface, fast user switching, improved remote administration, system restore and driver installation rollback. The system received two service packs and was released in the following editions:

  • Professional (basic version);
  • Home (with truncated networking capabilities);
  • Media Center Edition (with additional multimedia applications);
  • Starter Edition (highly limited, no online features);
  • 64-bit Edition (for Itanium processors);
  • x64 Edition (for processors with AMD64 or EM64T extensions);
  • N (without Windows Media player);
  • Tablet PC Edition (for tablet computers);
  • Embedded (for embedded systems).

In April 2003, a server variation of Windows XP was released, called Windows Server 2003 and having an internal version of 5.2. Differences from Windows XP: .NET platform and IIS 6.0 web server included in the installation, improvements in Active Directory, built-in firewall, an extended set of utilities for system administration. The system was released in four editions: Web Edition, Standard Edition, Enterprise Edition and Datacenter Edition. The last three of them also came out in versions for 64-bit x86 processors, and Enterprise and Datacenter also came out for Itanium. Two updates appeared in 2005, Service Pack 1 and R2.