BIOS (said: bye-ohs) stands for Basic Input/Output System. BIOS is the low level system that controls your computer and access to hardware. Depending on manufacturer, F1, F10, F12, or DEL will load the BIOS instead of booting up the computer. There will be a brief message indicating which to press on most machines upon startup. The BIOS provides information on internal hard disks and optical drives, boot up sequence, power options, and allows saving a new configuration. BIOS information is usually listed on a blue screen with a combination of white and/or red lettering.