Your computer's Bios explained

In between Windows and the actual bits of plastic, metal and silicon that make up your PC is something called the Bios (Basic input/output system).

The Bios is a small operating system in its own right, burned into a Rom chip that sits on the motherboard, or, more frequently these days, is stored in flash memory, similar to the memory card in a camera.

The Bios tells the operating system what components the PC is made up of, how to talk to them and what to do. When thinking about this particular bit of the computer’s innards, it’s important to remember that you can control it. The Bios can be used to protect your computer, add new bits of hardware and troubleshoot problems.

But why tinker with the Bios in the first place? Well, if you intend to add an extra hard disk, start your computer from a CD or floppy disk, or add things like a sound or graphics card, then it’s worth knowing what the Bios can do.

While most manufacturers provide drivers for hardware they sell, it’s still necessary to make changes to the Bios from time to time. For example, while new drivers can be spotted automatically by the Bios while it starts up, many PC makers turn this setting off to make the computer boot faster. We’ll return to this particular trick later.

In this article, we’re going to explain how to get into the Bios, how to make changes to it and how to save them.

But before we start, one important point: the Bios is a pretty delicate thing to tinker with, and can cause serious problems if the wrong settings are applied. That said, if you are unsure of any changes you may have made, it’s possible to exit the Bios without saving those changes – of which more later.

Where to look
To enter the Bios, you first need to find out which key to press after switching the computer on. In the first seconds after powering up the PC, a large amount of text scrolls down the screen, and usually somewhere in there is an instruction to “Hit F7 to enter setup” or similar.

The specific key required changes from PC to PC, and if you miss the instruction on screen, try other keys. F1, F10 F11, F12 and the Delete (Del) key are some of the more frequently used. If the computer came with a manual, it’s also worth taking a look to see if there are any instructions about accessing the Bios.

Once you’ve hit the right key, the computer will drop into the Bios interface instead of loading Windows. Visually, the Bios normally appears in the form of white text on a dark background.

Navigating around the Bios involves using the keyboard rather than the mouse, so take a second to familiarise yourself with the controls required. In most cases, it’s possible to move from one option to another using the arrow keys.

The key to using the Bios successfully is to think before acting – read everything on each screen, and if you don’t understand what an option is or what it does, leave it alone until you do.

Another thing to check is how to exit the Bios. There are usually two options: leaving the Bios without saving changes and an option to save any changes made and then exit. If you are unsure of a change you’ve made, exit the Bios without saving changes and the PC’s operation will be unaffected.