What Is BIOS In a Laptop or PC?

When you press the Power button, the BIOS springs into action. It’s a program stored on a special chip inside your computer’s motherboard. BIOS is the bridge between your computer’s hardware (keyboard, hard drive, and memory) and the operating system. It checks all the essential components in your computer and ensures they are functioning properly. 

Then it hands them over to the operating system for them to be loaded correctly. In short, BIOS is the ignition system of your computer.

How does the BIOS work?

Now that you know what BIOS is in laptops and pc, let us look at what it does in detail. The moment you turn on your computer, the BIOS jumps into action. It’s stored on a special non-volatile memory chip called ROM (Read-only Memory), which makes it a part of your computer’s permanent memory. This means that it doesn't disappear even when you turn off your computer. The BIOS has a three-step operation:

STEP I – Power-On Self-Test (POST)

This is a quick health check. BIOS makes sure your – 

• RAM is working

   

• Keyboard responds

   

• The hard drive is connected

   

• Storage devices are functioning

If something is not right, you will hear beeps or see an error message.

STEP II – Boot Order Check

BIOS checks for the sequence or order of devices it should try to load your operating system.  The usual order is:

1. Hard drive

    

1. USB drive

    

1. CD or DVD if one is inserted.

    

This is an order that you can change in the BOS settings.

STEP III – Boot Loader

• BIOS loads a program called Boot Loader. 

   

• This program helps the BIOS to hand over the baton to your operating system – Windows, Linux, or Mac, whatever you may be using.

   

• The Operating system takes over your computer, and you see your familiar desktop.

   

Why Is BIOS Important?

The importance of BIOS can be understood from the following points:

• Your computer’s start manager: Without BIOS, your system won’t know how to turn on. It makes sure that your laptop or desktop is ready to begin.

   

• It is a checkpoint: Check if all your hardware is running correctly before any other component in your system starts. It prevents faulty hardware from damaging your system during start-up by causing a crash.

   

• Customised settings: You can tweak BIOS settings to change your system behaviour, for example, boot order, virtualisation, or security passwords.

   

• Acts as a bridge: It translates the language of the operating system so that it can work compatibly with your hardware components, such as a keyboard, mouse, or hard drive. It thus builds a bridge between all your hardware and software, enabling your system to operate smoothly.

   

• Assists with troubleshooting: If your system has difficulty starting, the BIOS provides the first clues and tools to solve related problems.

   

Where Can You Access BIOS Settings on a Laptop or Desktop?

You can reach the BIOS settings on your laptop or desktop during:

• Startup: While your computer is booting up, you can access BIOS settings. In other words, immediately after you power on your desktop or laptop, but before it has loaded your operating system.

• Press the right key: Immediately press F2, F10, F12, Delete, or Esc after pressing the power button. The exact key is displayed on the screen and varies by manufacturer. You have only a few seconds to press the key before your OS starts loading.

• Brief on-screen prompts: Most computers display prompts like “Press F2 to enter setup” for only a short moment. In case you miss it, restart your computer and try again. Multiple attempts will not harm your system.

• Brand-wise key list:

   

F2: Dell

Esc or F10: HP

F1 or F2: Lenovo

F2 or Delete: ASUS / Acer

• Alternative method: On Windows 10/11, you can access UEFI settings through Settings > Update & Security > Recovery > Advanced startup

   

Conclusion:

It is easy to take the BIOS for granted since you don’t need to interact with it every day. But it is the silent worker who labours behind the scenes to bring you a seamless computer experience. It acts as the interface between your hardware and operating system. Understanding the BIOS gives you valuable insight into how your computer functions at a fundamental level. 

It holds the key to troubleshooting startup issues and changing boot priorities. At the end of the day, it simply lays the foundation for all the complex operations that your computer performs.