A computer’s basic input/output system (BIOS) is the program that acts as an interface between the hardware systems and the software systems. There are a handful of occasions when a user would want to boot to BIOS, although they should generally avoid it unless specifically told to do so. The three most common reasons are checking the system status, changing the boot sequence and altering hardware configurations. With that in mind, it is possible to make a computer completely non-functional by altering settings in the BIOS. Changes should only be made if the user knows exactly what the outcome will be.
The BIOS program is integrated into the computer itself and is not part of any installed program. It is the first program run by most computer systems and it provides the basic language spoken by the computer’s hardware and software. Most BIOS systems display their boot key when the computer first loads up. This key is usually displayed at the bottom of the screen with a message along the lines of ‘Press X key to enter setup.’ The key to boot to BIOS varies based on manufacturer and age, but ‘F2’ and ‘Del’ are both very common.
In order for the computer to recognize the key press, it needs to be entered before the computer finishes its power-on self-test. This process, commonly called ‘posting,’ is usually accompanied by a single beep and a system status display. If the user misses the boot to BIOS window, the computer will need to be restarted for another attempt.
Altering the boot sequence is one of the most common reasons for new users to enter the BIOS. The BIOS tells the computer the order it should use to find an operating system. If a user installs an operating system on a new drive and wants the computer to boot to it directly rather than to an older install, it is possible to switch the order in which the computer looks for programing. Changing this order will also prevent bootable disks from interrupting a boot should they be left in the drive.
Being prompted to boot to BIOS to check system status is generally straightforward. Many BIOS systems maintain internal catalogs of hardware, system time and temperature. If a computer is acting strange or a piece of hardware isn’t being recognized, these lists may hold answers as to why.
The last, and most dangerous, reason to enter the BIOS is to alter hardware configurations. This process, commonly called overclocking, allows users to alter the way the computer powers and uses various pieces of hardware. The most common BIOS overclocking is done to the computer’s memory, chipset and processor. Configuring any of these components incorrectly could permanently damage a computer.