7. BIOS The Bios (built in operating system) is as its Greek name tells us. 'Bios' is life and this chip is the life of the computer. When the computer is started the bios tells it what kind of computer it is and where to find the information it needs to POST (Pre-operation start-up test). Your Bios is built to work with the motherboard, and changing the Bios is a job for experts.