According to statistics, every third user of a computer or laptop sooner or later faces the fact that he has to restore the operating system or even reinstall it. It doesn't matter which one - be it Windows, Linux, BSD or something else. In most cases, you need to force the computer to boot from external media - a CD / DVD drive or a USB flash drive. All the instructions say "you need to go into the BIOS (BIOS)" of the computer. And here the average user asks the question - how to do it? Everything is very simple, but let's look at everything in order.

What is a BIOS?

The abbreviation BIOS stands for "Basic Input Output System". In Russian, this translates as "Basic Input-Output System." You and I can see her work in an explicit form at the start of the computer - a black screen with white letters and numbers.
On modern computers, this is no longer quite the BIOS, but its more advanced descendant - UEFI. In any case, this is the closest microprogram to the physical layer (ie, directly to the hardware). In a nutshell, when the computer is turned on, it tests the subsystems entrusted to it, after which control is transferred to the OS loader and only then to the operating system itself.

Why go there?

If you are a novice user, then once again it is better not to climb there, because changing BIOS parameters without a clear understanding of your actions will not lead to anything good. If you do not know the meaning of any parameters of the I / O system, then just do not touch them. Otherwise, it may end badly for your computer, which means your wallet will also suffer.
Most often, you need to go into BIOS to change the device initialization sequence and force boot from a USB flash drive or disk. Although on modern motherboards, the boot device selection menu can be called up by pressing a special button. The main thing is to carefully read the inscriptions at the bottom of the screen when loading.

How to enter BIOS (BIOS) on a regular computer

In fact, the sequence of actions is the simplest:
- turn on the computer
- look at the inscriptions at the bottom of the screen. We are interested in something like "Press Del to Enter Setup".

On 90% of the motherboards that I have met, in order to enter the BIOS, you need to press the button. On some models, or .

I have not seen any other options on simple stationary computers.
- quickly press the indicated button several times and get into the BIOS or UEFI - it all depends on your motherboard:

If you missed the moment and the download started (which is not surprising on a modern computer with an SSD - after 10 seconds we have an already working OS), then just reboot and repeat the steps.

How to enter the BIOS (BIOS) of a laptop, netbook or ultrabook

In mobile devices, things are a little more complicated, but I emphasize - a little. The principle is the same - when loading, you need to click on the desired button. Moreover, what operating system on the laptop would not be Windows 7 or Windows 8 - there is no difference. The only difficulty that can lie in wait for you is the fast loading of the device. That is, while you read the inscriptions and think about which button to press, the laptop will already start loading the operating system. On some models, pressing the button can help to pause the system boot:

Again, most often users climb into the BIOS of a laptop to select a boot source in order to set the first flash drive. On modern models, there is a separate key to select the device from which the download will proceed. Most often it is , or .

Very rarely, but there are cases when you need to press the key combination - +, +, ++[S], ++, ++ or +[S] to enter. Other options are almost non-existent.

Entering the UEFI BIOS (UEFI) - is there a difference ?!

In terms of access - no, everything is the same. UEFI is a modern version of computer software that replaces the already obsolete BIOS in all respects and performs its functions. To enter its parameters, you must press the button in the same way when you start your computer or laptop.

Just in case, I will give a list of manufacturers and the buttons they use to enter the BIOS and UEFI BIOS:

Acer(Aspire, Power, Veriton, Extensa, Ferrari, TravelMate, Altos): Press or
Acer(old PCs): Press or ++
AMI(American Megatrends AMIBIOS, AMI BIOS): Click
AMI(American Megatrends AMIBIOS, AMI BIOS) - old versions: Press or
Award BIOS(AwardBIOS): Press button
ALR
ARI: Press ++ or ++ while booting
AST Advantage: Press ++ while downloading
Compaq(Presario, Prolinea, Deskpro, Systempro, Portable): Press when logo is displayed
Compaq(old computers): Press the button , , , or
cybermax: Press the button
Dell(XPS, Dimension, Inspiron, Latitude. OptiPlex, Precision, Vostro): Press F2 when the Dell logo appears
Dell(old 486 models): Press ++
Dell(some models): Press the Reset button twice
Dell(Old laptops) : Press + or +
DTK(Datatech Enterprises): Press the button immediately after power on.
EISA Computer: Press the key combination ++ or ++[S] as soon as the RAM test starts
eMachines(eMonster, eTower, eOne, S-Series, T-Series): Press or
eMachine(Some Older Computers): Click
Fujitsu(LifeBook, Esprimo, Amilo, Tablet, DeskPower): Click When Fujitsu Logo Is Appearing.
Hewlett-Parkard(HP Pavilion, TouchSmart, Vectra, OmniBook, Tablet): Press when the HP logo appears
Hewlett-Parkard(HP Alternative): Press or
Hewlett-Parkard(HP) Tablet PC: Press or
IBM ThinkPad on IBM BIOS(older models): Press ++ when the cursor is in the upper right corner of the screen
IBM ThinkPad on IBM BIOS(new models): Press and hold while power on
IBM ThinkPad on Phoenix BIOS: Press ++ from DOS prompt
IBM (PC, XT, AT): Press immediately after power on
IBM(Old computers and laptops): Click
Lenovo(ThinkPad, IdeaPad, 3000 Series, ThinkCentre, ThinkStation): Press or
Lenovo(old models): Press ++, ++ or +.
Microid Research MR BIOS: Press
Micron(MPC Computers ClientPro, TransPort): Press , or
NEC(PowerMate, Versa, W-Series): Press button
NEC Versa Notebook: Press and hold while turning on the PC
Olivetti PC Pro: Press +++ on the numeric keypad
Packard Bell(8900 Series, 9000 Series, Pulsar, Platinum, EasyNote, imedia, iextreme): Press , , or .
Packard Bell(old models 386 and 486): Press combination ++[S]
Phoenix BIOS(Phoenix-Award BIOS): Press during system self-test
Phoenix BIOS(Phoenix-Award BIOS) - old versions: Press ++[S], ++, ++ or +[S] immediately after power on
Sharp(Notebook Laptops, Actius UltraLite): Click
Shuttle(Glamor G-Series, D'vo, Prima P2-Series, Workstation, X Mini XPC, Surveillance): Press or
Sony(VAIO, PCG-Series, VGN-Series): Press , or
Sony Vaio 320 Series: Press while booting
Tandon and Tandon 386: Press ++
Toshiba(Portege, Satellite, Tecra): Boot Button
Toshiba(Portege, Satellite, Tecra on Phoenix BIOS): boot button
Zenith, Phoenix: Press combination ++