What Does the BIOS Actually Do?

The BIOS (Basic Input Output System) is the basic software that every computer has. Among other things, it is used to identify and manage all computer components. It is an integral part of a computer and is found in a separate chip on the mainboard.

It is the first software to be loaded when the computer is switched on and checks, among other things, the built-in hard disks and DVD drives required to start the operating system, for their bootability.

When the components are working properly, the BIOS activates the appropriate drives to allow a computer’s actual operating system to boot.

Important functions and properties

In addition to quickly checking the drives, the BIOS is also used to control and change individual PC components such as the CPU. For example, in the BIOS settings of newer processors, you can adjust whether so-called overclocking, i.e. overclocking the CPU to optimize system performance, should be switched on.

Another important area is the boot sector. In this, users can manually specify which active components – i.e. hard disks and drives – should be started in which order when the PC boots up. Normally, the individual drives and hard disks are switched in such a way that the hard disk on which the operating system is located starts first and other components such as a DVD drive are controlled second.

However, there are situations when it is necessary to change the boot order. For example, if a new operating system is to be loaded onto a computer from a DVD, the boot order must be changed so that the DVD drive is loaded first at startup and not the boot hard disk.

Changing the boot order can also be useful if a hard disk cannot be started or you have two different operating systems on two hard disks. In addition, a BIOS chip is a control tool that keeps track of how high the CPU’s temperature is, how much power is being consumed and the like.

Experienced users can use this information to change the settings of their hardware components, which can improve performance or reduce the power consumption of the PC.computer BIOS

The ability to update the BIOS

The BIOS on a mainboard is often outdated at some point and you can find a more recent version from the manufacturer of the mainboard. The only question is whether an update, also known as ” flashing the BIOS “, is necessary at all. Because as long as everything works without problems and all hardware components are recognized, an update is actually superfluous.

It would only really matter if, when assembling a PC, there were difficulties in agreeing on the drives or the mainboard and the graphics card, for example. And even then, an update should be seen rather critically.

Because if an error occurs during the update, which can happen due to a power failure or an incorrect download of the software, things quickly get really bad. As a user, you are then faced with the problem: the BIOS does not start. In the worst case, the PC can no longer be started at all and must be repaired by a specialist.

Therefore, as long as everything works correctly, you don’t have to carry out an update. Should an error occur during the update, there are various suppliers where you can buy new BIOS chips for mainboards and notebooks for little money. Usually, the latest BIOS version is already installed there.

BIOS beeps and what they mean

This often happens when the computer no longer starts and beeps can be heard. With these beeps, the computer tries to tell us what’s wrong. So it would be handy to know what the most common beeps mean.

This situation can occur in particular when a new computer is assembled. It’s helpful if you know roughly where to look.

The most important beeps:


  • 1x: RAM defective or not properly plugged in
  • 6x: Keyboard defective or missing
  • 8x: Graphics card defective or not installed correctly
  • 11x: Checksum error, the mainboard battery may be empty


  • 1x long: RAM defective or not properly plugged in
  • 1x long 2x short: Graphics card defective or not installed correctly
  • Continuous tone: Graphics card or keyboard is missing
  • 1x long 3x short: keyboard defective or missing, with newer versions it can also be a defective graphics card

Phoenix BIOS:

  • 1x-1x-4x: BIOS faulty
  • 1x-2x-1x: Mainboard defective
  • 3x-1x-1x: Mainboard defective
  • 1x-3x-1x: memory problem
  • 3x-3x-4x: Graphics card defective or not installed correctly

If the problem cannot be clearly identified from the beeps, you can also seek the help of other users in a computer forum or another community.

In this way, you can solve many problems yourself without using a paid repair service.the BIOS functions

Forgot BIOS password

The following problem often comes up. You want to change a setting in the bios, but you have forgotten the password or you have dusted off a cheap PC from Ebay and Co. and cannot get into the bios.

But there is a way. The method described below will also reset all settings to the default values. That’s nothing bad, but the settings should definitely be checked and corrected if necessary.

Start the computer with a DOS start-up disk and enter the debug.exe command in MS-DOS. Now type in the following commands:

-o 70 2e
71ff -q

After restarting the computer, a CMOS error message will appear. The good thing is that you can now enter the BIOS without any problems. But as I said, all settings are set to the default values. Check and correct if necessary!

However, nowadays one has to ask: Whose computer still has a floppy disk drive?

Since this method involves some risks, you should perhaps try two other options beforehand.

Delete BIOS password – This always works

Do you want to delete the BIOS password? Then you can try the following: Check the manual for the mainboard or directly on the mainboard to see if there is a jumper labelled CLEAR CMOS or something similar. If such a jumper is present, you can restore the default values ​​( BIOS reset ) by changing the position and thus also delete the password. But the same applies here: After the restart, check the BIOS settings and correct them if necessary.

If this jumper is not available, you can also try the following. The computer is switched off, just like before changing the jumper. To be on the safe side, disconnect the computer from the socket and remove the small, round battery on the mainboard. Incidentally, this is also how you proceed if you want to change the BIOS battery, because the date and time may keep changing.

After about 10 minutes the BIOS should be reset…

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