Hello, unfortunately sometimes it happens that Windows does not want to boot due to and it gives an error, just at the wrong time. Here I will give a list of programs that can help you recover a crashed bootloader.
1. Partition Table Doctor is a unique program for recovering damaged disk partitions. Damage can occur as a result of an unexpected loss of power, or a virus attack, as a result of which the disk stops displaying any information (behaves as if it were fresh from the factory).
The program automatically checks and restores the Master Boot Record (MBR), the file allocation table, and the boot sector of the partition. The following file systems are supported: FAT16, FAT32, NTFS/NTFS5, EXT2, EXT3, SWAP.
The program can create a rescue floppy (Ctrl+D inside the program). Included is a bootable image in IMA format for burning a rescue CD. In Nero 6, this is done as follows: start Nero, select CD-ROM (Load) in the new project menu, switch to Image file and through "View" we find "PTD Boot.ima". Now you can click "New" and cram anything into this compilation. The burned disc will be bootable, i.e. if your computer is booted from a CD drive, a DOS version of Partition Table Doctor 3.5 will appear.
2.DiskPatch is a professional data recovery utility based on DOS that recovers data by restoring damaged disk structure such as partition tables "in place".
DiskPatch is designed to solve most of the problems that prevent you from accessing your data; corrupted MBRs (Master Download Records), corrupted partition tables, unexpectedly deleted partitions, bad boot sectors, and bad sectors.
Damage to the MBR, partition tables and parts of bootable sectors in most cases leads to massive data loss; situations where you cannot access a partition or an entire hard drive. You can fix these issues yourself using DiskPatch!
DiskPatch automatically repairs damaged, corrupted or lost partition tables and bootable sectors. Fast. Just. Safely.
To make disaster recovery easier, DiskPatch allows you to back up important disk structures such as the MBR, partition tables, and bootable sectors.
3. Using the boot disk which includes bootloader recovery program — MBR fix
4MBR Editor- A program for editing the Master Boot Record (MBR) of a disk.
Capabilities:
– viewing and editing the Disk Partition Table;
– viewing and editing Boot sectors (Boot Sector)
sections;
– saving/loading the entire BMR to/from disk(s);
– saving/loading the Boot Loader to/from disk(s);
- restore bootloader from templates (Windows XP Professional SP2,
Windows 98 SE, MS-DOS 6.22);
But sometimes programs do not help and you have to, which is the most reliable tool.
Communication with a personal computer does not always consist of joys and pleasures alone. Sometimes there are troubles, problems and "troubles". Sometimes, it happens that Windows cannot boot, and instead of the usual welcome screen, we observe a more than a dull situation: the computer freezes tightly and does not respond to anything, or goes into a constant reboot without even having time to open a single window. It happens that the start of the computer is interrupted, and several white lines of English text appear on the monitor on a black background, or a completely incomprehensible blue screen is displayed with a bunch of incomprehensible numbers and letters ( BSOD, IT-specialists have not without reason nicknamed this screen " blue screen of death"). No matter how it looks outwardly, only one thing is clear - the operating system is out of order.
There can be a lot of reasons for this situation - power surges while working with a computer, the harmful effects of viruses, device or program conflicts, or simply the user's "crooked" hands or something else. Such a situation will not cause surprise for a sufficiently experienced person, except it can only cause annoyance if, for example, there are a lot of cases and messing around with restoration is completely inopportune.
All these problems are easily solved by a complete reinstallation of the operating system - in capable hands it takes less than an hour and does not present any difficulties. But in addition to Windows itself, many third-party programs can be installed in the operating system, which then have to be reinstalled and configured again. It also happens that some important data is saved directly to desktop or on the system partition (which experienced users do not allow) and, of course, will be destroyed during reinstallation. Or just in any situation, time is money. What to do in this case, you ask?
You can try to restore the health of Windows XP using several built-in functions prepared in advance by Microsoft.
Loading Last Known Good Configuration
We hold down at system startup, as soon as information about the BIOS and found devices disappears from the monitor, the key F8 on the keyboard (on some computers you will have to not just press and hold, but press this key several times at a fast pace) and wait for the safe mode menu to load.
In this menu, white lines on a black background list the emergency boot options for Windows. The very first thing we need to try is the " Loading Last Known Good Configuration (with working options) ". If the failure is not of a global nature, selecting this item quite often helps to start the system in normal mode. Did it help? Read on.
Safe mode
We go into the safe mode menu in the same way as described above, and select the top line - " Safe mode". This type of Windows boot is perhaps the most important in case of any problems with the system. Unlike the usual one, it does not start all system services and does not load all drivers at boot - it works at the "very minimum". and only the most necessary for the operation of the system is loaded. Desktop, do not be afraid that everything looks unusual - it's just that video drivers are not loaded in this mode. You can try on your own to find out the cause of the problem and fix it (if you have enough knowledge and experience for this). Or, in extreme cases, "evacuate" important data (save "s of toys, for example, or important program settings) from the system partition to a safe place so that you can safely reinstall the operating system without fear of losing them.
If you know for sure that some program caused the crash, you can try to uninstall it in safe mode (however, it is not always possible to run the Windows installer in this mode), and then try to reboot.
You can try to run System Restore (unless, of course, you turned it off, as many "unfortunate optimizers" advise) and roll back Windows to another checkpoint - very often this solves all problems. To launch it, let's go Start -> All Programs -> Accessories -> System Tools and choose System Restore. Unfortunately, sometimes this service fails to start in safe mode.
In general, if you are not a computer "super-pro", I do not recommend disabling this service - quite often it saves the system from reinstallation (although not always), and its operation is almost imperceptible with the power of modern computers. It is only important to correct the default settings for more reasonable ones. It is done like this: Start -> right click on My Computer -> Properties and select tab System Restore. Here, in a small window, select each section in turn and, by clicking Options, set individual settings for it. Personally, I set it like this: For the partition where the operating system is installed, using the slider, I set the size limit to about 1 GB, and completely disable recovery on all other disks so as not to waste space on the hard drive. You set it up as you see fit.
Restoring Windows from a boot disk
If the cause of the failure could not be eliminated, or at least Safe mode and it worked, but reinstalling Windows is highly undesirable for fear of losing important programs, or just a waste of time, you will have to use the help of the Windows XP boot disk from which you installed the operating system.
Note. Some Windows homemade build discs are sometimes missing necessary tools.
Insert the disc into the drive and boot from it by setting the BIOS to boot from the drive first.
How to enable priority boot from the floppy drive in the BIOS. At the very beginning of the computer boot, as soon as the BIOS information passes, we hold and hold (or often press) the key Delete(Del) until the BIOS setup menu appears. We are looking for a section in it where the order of boot devices is indicated (we move using the arrow keys, and select with the key Enter, back - Esc). In the Award BIOS, this is the section Advanced, in AMI BIOS - section BOOT. In other options, you will have to find these options yourself - look for everything related to boot(loading). After the partition is found, you need to change the settings so that your drive becomes the very first boot device (or the top one in the list of boot devices). Changed? Save changes by clicking F10, and answer the next question by clicking " Y"("yes"). The computer will restart and the next time it starts, it will boot from the disk in the drive first. Do not forget later, when you fix everything, return the settings back, because this boot order is not very convenient in everyday use of the computer.
By the way, some laptop models allow you to briefly, for once change the boot order without getting into the BIOS settings. To do this, at startup, press several times F12 and in the small menu that appears, select your drive. You don't need to return anything later - at the next boot everything will be as usual.
Entering the settings of some BIOS versions is not carried out by a key Delete, and, for example, F2 or other. You can accurately determine this from the BIOS information at the beginning of the boot - carefully look at the very bottom of the screen, in the left corner an indication of the desired key will jump there.
So, we reboot from the disk in the drive. As soon as the sign appears Press any key...(or similar), you will only have 5 seconds to boot from disk by pressing ANY key on your keyboard. If you do not have time, the computer will start to boot from the hard drive, and you will have to reboot again.
Did you press everything in time? Wait for the first dialog box to appear:
Click Enter. Installation will begin (Windows is installed on the same partition, the file system is left unchanged). After you have read the license agreement and agree to it by clicking F8, the installer will check your hard drive for installed versions of Windows XP. Having found one, he will offer to restore it. Agree with this by pressing the key R .
The further procedure resembles the usual installation of the system - the license key is also entered, the region and time zone are selected, etc. At the end of the process, which lasts approximately the same as a normal installation of Windows XP, all the files necessary for work will be restored and no data and programs will be affected - everything will remain in place. You may just have to update the drivers, but this is not always necessary. And all programs with all data and settings will remain intact.
NOTE. If, in parallel with XP, you have Windows Vista installed on the same hard drive, it is most likely that this method will not work for you - Vista, as a rule, overwrites all boot records and files and replaces them with its own, prescribing one single operating system on the hard drive - himself-beloved, and only then includes in his files records for loading other operating systems. As a result, the Windows XP installer, of course, simply does not find any system to restore. You can try in such a situation to first rewrite the boot sector using the Recovery Console with the commands fixboot or fixmbr(read below), and then, having completely restored Windows XP, restore the Vista bootloader from under it. This process is described in sufficient detail.
Recovery Console
Sometimes such a global Windows restore is not required and you can try using the built-in utility called Recovery Console .
In those situations where the boot record or boot files are corrupted, the Recovery Console is the easiest and fastest way to solve the problem.
To enter it, you need, as in the previous example, insert a boot disk and wait for the first dialog box to appear (see the second screenshot). Only now we should not click on Enter- we are interested in Recovery Console, so we press R and wait until the list of operating systems installed on the computer appears on the screen.
If you have only one Windows (like most users), just click first 1 , and then Enter. If there are several operating systems installed, select the one you need.
Next, you will be asked to enter the administrator's name and password. If you have not changed them, then leave these two fields as they are and double-click Enter. You will now see this text on the screen: C:\Windows"You have reached your destination.
In this article, we will describe only a few commands that we will need. If you want to use all the possibilities that the Recovery Console can provide in the future, you will have to search the Internet for a list of all commands and tips on their use. You can also get some information from the built-in documentation by typing HELP or /? . To get a description of each of the commands, you can add the key /? (for example, chkdsk /? or HELP chkdsk ).
fixboot command
This command fixes the boot sector of the hard disk, that is, it provides the computer with the necessary information to boot the operating system. With its help, you can eliminate a fairly common malfunction, when instead of the expected "windows" we see an inscription on a black background " NTLDR is missing".
The appearance of such a window clearly indicates damage to the boot record. Among the most likely causes of this error are problems with the power supply, improper shutdown of the computer, or "experiments" with installing different operating systems other than Windows on the same hard drive.
With the help of this command, the problem is solved elementarily. We type in the command line that appears fixboot, agree that we really want to overwrite the boot sector by pressing Y .
fixmbr command
Performs the same actions as the previous one, with the only difference that in this case, the entire boot sector is completely overwritten.
chkdsk command
Scans the hard drive for errors. If you run this command with the key r (chkdsk /r), all found errors will be automatically corrected. Quite often, this command helps to restore Windows and save all data on the system partition.
All the options we have considered do not guarantee 100% recovery of the Windows operating system, since everything directly depends on the cause of the malfunction. However, in most cases, these methods help to quickly and without loss restore normal performance.
Last tip. Take care not to store any important data on the system partition of the hard drive. Otherwise, in the event of an unexpected crash of Windows and its unplanned reinstallation, this data may be irretrievably lost. Think carefully about a file storage system that is convenient for you by creating various folders on other sections of the hard drive. And in the future, save data to these folders. it should also be remembered that Desktop- this is also a special folder on the system partition, just like My documents, where all pictures, music, etc. are saved by default. By the way, you can change the location My Documents moving them to another section. It is done like this: Start -> right click on My Documents -> Properties. In the window that opens, select the tab Destination folder and by pressing Move..., indicate the location.
That's all for today. Good luck!
Bootmgr and ntldr are standard bootloaders, but they are designed for different operating systems. Bootmgr- This is a more recent version of the bootloader, which has been used since Windows 7. It characteristic faster data processing and the ability to load the maximum version of the operating system. In addition, is new generation implementation of the interface between computer hardware and operating systems, and in the near future, will completely replace the BIOS model that has existed for several decades.
In its turn, ntld used on old OS versions (Vista and XP). This bootloader different slow data processing and the ability to handle simple tasks.
New bootmgr boot manager oriented to use a special BCD (Boot Configuration Data) boot configuration store, as well as specially developed applications and specification data EFI. For compatibility with versions of Windows prior to Windows Vista, the new BOOTMGR manager provides support for booting operating systems from previous generation BIOS-based computers.
Restoring the bootloader in Windows XP
To date, many users still use Windows XP on their personal computers, and due to the fact that this version of the OS is already outdated, there may be failures in the bootloader, to correct which can be as follows:
If, when restarting Windows, it displays a message NTLDR is missing, then the cause of the problem is due to the fact that the boot record was completely deleted. To solve this problem would need:
If such problems occur on Windows Vista, the actions are similar, since the same type of bootloader is used.
Fixing the bootloader in Windows 7
Windows 7 uses a new type of bootloader, which is why there is several ways its recovery.
We use boot from disk or flash drives:
But, this method can only help if the damage to the bootloader is minimal. At more serious problems, you should use the boot.ini editing process.
Usage bootrec:
Troubleshooting Windows 8, 10
Windows 8 and 10 use the same type of bootloader (however, in Windows 10, it has increased the speed of processing various operations). Therefore, the restoration of this element occurs in a similar way.
Automatic recovery
As a rule, automatic recovery is enough to normalize the operation of the entire operating system.
Operating system usually stored in the external memory of the computer - on the disk. When you turn on the computer, it is read from disk memory and placed in RAM. This process is called operating system loading .
The disk on which the OS files are located and from which it is loaded is called systemic.
Programs can only run if they are in RAM, so OS files need to be loaded into RAM.
After turning on the computer, the OS is loaded from the system disk into RAM. The download must be performed in accordance with the boot program - the OS loader.
The phased loading of the OS can be represented as follows:
The computer contains a ROM containing programs for testing the computer and the first stage of booting the OS, which are called BIOS (Basic Input / Output System - basic input / output system). After turning on the computer, these programs begin to run. Moreover, information about the progress of this process is displayed on the display screen. First, the hardware is tested and configured, then the OS starts loading. At this stage, the processor accesses the disk and looks for the presence of a small bootloader program in 1 sector of the disk. MasterBoot.
Master Boot looks for the main bootloader on the disk BootSector, loads it into memory, and passes control to it. Bootsector(boot sector) - part of the disk reserved for the OS boot program. This sector usually contains a short machine language program that loads the OS.
Next, the main loader looks for the rest of the operating system modules and loads them into RAM.
After the OS is loaded, control is transferred to the command processor. If the command line interface is used, the system prompt appears on the screen, otherwise the graphical interface is loaded.
Depending on the type of OS, the boot process will be different. The composition of the OS necessarily includes files responsible for the boot process. Consider the "work" of files in the process Windows XP downloads.
- Initial loading phase.
- System selection.
- Definition of "iron".
- Configuration selection.
In the initial phase, NTLDR switches the processor into protected mode. It then loads the appropriate file system driver to work with files in any file system supported by XP (FAT-16, FAT-32, and NTFS).
If there is a BOOT.INI in the root directory, then its contents are loaded into memory. If it has entries for more than one operating system, NTLDR stops working - shows a menu with a choice and waits for input from the user for a certain period of time.
If there is no such file, then NTLDR continues to boot from the first partition, the first drive, usually C:\.
If during the selection process the user selected Windows NT, 2000 or XP, then pressing F8 and showing the corresponding menu with boot options is checked.
After each successful boot, XP creates a copy of the current combination of drivers and system settings, known as the Last Known Good Configuration. This collection can be used to boot in case some new device has brought a rift to the operating system.
If the selected operating system is XP, then NTLDR finds and loads the DOS program NTDETECT.COM to determine the hardware installed in the computer. NTDETECT.COM builds a list of components, which is then used in the HARDWARE key of the HKEY_LOCAL_MACHINE branch of the registry.
If the computer has more than one hardware profile, the program stops with a configuration selection menu. After selecting the configuration, NTLDR starts loading the XP kernel (NTOSKRNL.EXE). During the kernel boot process (but before initialization), NTLDR remains in charge of computer control. The screen is cleared and an animation of white rectangles is shown at the bottom. In addition to the kernel, the Hardware Abstraction Layer (HAL.DLL) is also loaded so that the kernel can abstract from the hardware. Both files are in the System32 directory.
NTLDR loads device drivers marked as bootable. Having loaded them, NTLDR transfers control of the computer further. Each driver has a key in HKEY_LOCAL_MACHINE\SYSTEM\Services. If the Start value is SERVICE_BOOT_START, then the device is considered bootable. For each such device, a dot is printed on the screen.
NTOSKRNL during the boot process goes through two phases - the so-called phase 0 and phase 1. The first phase initializes only that part of the microkernel and the executive subsystem that is required for the main services to work and continue loading. Phase 1 begins when the HAL prepares the system to handle device interrupts. If the computer has more than one processor, they are initialized. All executive subsystems are reinitialized in the following order: Object Manager, Executive, Microkernel, Security Reference Monitor, Memory Manager, Cache Manager, LPCS, I/O Manager, Process Manager.
Initializing the I/O Manager starts the process of loading all system drivers. From the point where NTLDR left off, drivers are loaded by priority. A failure to load a driver can cause XP to reboot and attempt to restore Last Known Good Configuration. The last task of phase 1 of kernel initialization is to start the Session Manager Subsystem (SMSS). The subsystem is responsible for creating the user environment that provides the NT interface. SMSS runs in user mode, but unlike other applications, SMSS is considered a trusted part of the operating system and a "native" application (uses only executive functions), which allows it to run the graphical subsystem and login. SMSS loads win32k.sys, the graphics subsystem. The driver switches the computer to graphical mode, SMSS starts all services that should automatically start at startup. If all devices and services started successfully, the boot process is considered successful and a Last Known Good Configuration is created.
The download process is not considered complete until the user is logged into the system. The process is initialized by the WINLOGON.EXE file, which runs as a service and is maintained by the Local Security Authority (LSASS.EXE), which shows the login dialog. This dialog box is shown around the time the Services Subsystem starts the network service.