4 Important Functions of BIOS in Computer & Types of BIOS

Do you know what is BIOS, How it works & what are the functions of bios in computer? You will know about all these things in this article.

Nowadays official work is done through computer. You too must be reading this article on your laptop, desktop, or mobile. A computer is made up of two things, hardware, and software.

I have talked about this hardware and software in the previous article. So, today we will learn about the small and important hardware of the computer which is called as Bios and the software put inside it.

So without delay, know what is the basic input output system in the computer.

What is BIOS in the computer?

The full form of Bios is Basic Input Output System. It is an important part of a computer. Basically, Bios is an IC, which is installed in the computer’s motherboard. By programming this bios IC, it is installed in the motherboard. The computer can be started due to this basic input output system IC.

When the computer boots up, the BIOS checks for all connected devices in the computer and configures them all with the computer. If the device is faulty, then the computer does not detect it. Your computer may have this problem sometimes saying “Operating system not found, please press ctrl+alt+delete button“. This problem is shown to you through bios

Because it has 2 reasons. First, if the operating system in your hard drive is corrupted, otherwise the hard disk will not be properly connected to the computer. Due to these two reasons, the bios prevent the computer from starting.

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Bios (Basic Input Output System) comes under the primary memory of the computer. We also call it ROM memory. It first checks all the hardware of the computer like RAM, processor, keyboard, mouse, hard drive, etc, and only then loads the operating system into the computer memory.

In bios, information about almost all the parts of the computer and some system drivers are kept inside it. which was installed by the motherboard manufacturer. This program cannot be changed, but by resetting it, the same program can be reinserted or the program updated.

4 functions of BIOS in computer

There are different instructions in the BIOS to load the hardware of the computer. So that it plays the main role in starting the operating system. Some of the major functions of the bios are given below.


The full form of POST is Power on Self-Test. This means that when the computer is started, only then do the bios first check all the hardware. From this, it is known whether there is any hardware part fault or not. Only after that does the computer boot. If there is a problem with any parts of the computer, then the Bios informs the user with the beep code sound. How many beeps sound comes in which problem is given below.

Beep CodeProblem
1 short beepDRAM refresh failure
2 short beepsParity circuit failure.
3 short beepBase 64 K RAM failure.
4 short beepSystem time failure.
5 short beepProcessor failure.
6 short beepKeyboard controller failure
7 short beepVirtual mode exception failure
8 short beepDisplay failure
9 short beepROM BIOS failure.
10 short beepCMOS shutdown failure.
11 short beepCheck failure

If the above problem did not happen then there would be no beep sound. After that, the BIOS gives instructions to load the operating system on the computer.

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Bootstrap Loader

The bootstrap loader is a functions of the bios. After the BIOS self-checks all the parts of the computer, then the BIOS locates the boot file of the operating system and loads it into the computer. This process is called a bootstrap loader.

BIOS Driver

When the operating system is loaded into the computer, all the hardware parts installed in the computer are controlled by the driver itself. This instruction is given by BIOS to all those hardware drivers so that all those parts can run properly. Such as sound driver for sound device, USB driver for USB device, ethernet driver for internet connection, WIFI driver for WIFI, etc.

CMOS Setup

CMOS stands for Complementary Metal-Oxide Semiconductor. It stores the basic programs and settings in the computer in memory. it is a small cell in which information such as the date and time of computer, password, device settings, etc. is saved. After removing it, all these settings of the computer are reset.

If this cell is correct, even turning off the computer does not reset all these settings. Because this setting is stored in the Bios and the Bios program run from the CMOS battery. So it comes under the non-volatile memory.

Different types of BIOS (Basic Input Output System)

When you start the computer, only then there is an option to go inside the Bios (Basic Input Output System) program below on the Welcome Screen. This is not known to all computer users. Going to the Bios option of the computer shows how many types of Bios are there. Generally, there are 2 types of Bios.


The full form of UEFI is Unified Extensible Firmware Interface. This is a modern bios program. It supports MBR (Master Boot Record) instead of using GPT (GUID Layers Table) technology. This bios firmware supports large drives. However, this BIOS firmware allows the hard drive to be included in the automatic master boot record. If you need to format your hard drive or insert a new operating system, then first you have to convert the hard drive from MBR to GPT format.

Legacy BIOS

This bios is found in older motherboards or older computers. One of the reasons for moving from legacy bios to UEFI bios is that legacy bios is not capable of supporting very large drives. basically, It can be operated only with a keyboard.

What was the first BIOS?

Gary Kildall first developed the BIOS in 1974. Which was used in the CP / M operating system. Kildall invented the term “BIOS” to define a part of a system that, when the system is loaded, communicates with the rest of the hardware devices to make the computer run optimally.

BIOS upgradation

Often you might have noticed that upgrading a computer does not support some newly installed devices. Such as graphics card, hard disk, LAN card, etc. This happens because of the bios in that computer. Because it supports only as many devices as it is programmed in that bios to support. It doesn’t have a program to support newer devices.

This problem is solved only after upgrading the bios. Generally, the setup to upgrade the bios is done on the official website of the motherboard. If you want to upgrade bios, first backup your important data from the hard disk, then upgrade the bios.

Moreover, sometimes the BIOS program gets corrupted, and the computer is not able to boot. So for this, the Bios IC which is installed in the motherboard is removed and reprogrammed through a kit called Bios Programmer. Afterwards reprogramming the BIOS IC, the computer starts. Basically, the BIOS IC is located near the processor and Northbridge.

BIOS Manufacturers

There are so many manufacturers of BIOS, list is given below.

  • IBM
  • Dell
  • Phoenix technologies
  • AMI (American Megatrends)
  • Insyde software

Advantages of BIOS

  • Due to the presence of BIOS in the computer, it makes it easy to run the computer by giving precise instructions to all the other devices installed in the computer.
  • Due to Bios, you can provide security to your computer or laptop and be able to password protect your system with the help of the Bios option.
  • If there is a problem in any device like sound, network, keyboard, display, etc. in the computer, then the BIOS informs the user about this problem with a beep sound.


In conclusion, after reading this article you must have understood well Importance of BIOS in computer system, important functions of bios & different types of BIOS in computer. To conclude the article, BIOS is an integral software of the computer without which the computer cannot start.

In particular, the BIOS links the basic components of the computer together and all other programs on the computer, such as those in the operating system, run only after the BIOS is run.

I hope that in this article you must have known about the functions of BIOS (Basic Input Output System). If you have any doubt about this then you can tell in the comment box. We will do our best to solve your doubts. If you like this article then share it with your friends on social media. Thanks for reading this article.

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