Tom's Hardware has an amazingly comprehensive BIOS guide that covers everything from the basics to hardcore tweaking. This guide rivals my old favorite BIOS optimization guide over at Adrian's Rojak Pot. For PC's, a BIOS is a small CMOS chip on the motherboard that controls the very basic, low-level functions associated with configuring your PC's hardware settings. BIOS is an acronym for Basic Input Output System and is responsible for all of the gibberish that appears on your screen when you first boot your computer. Gamers use it to overclock their processor and lower their RAM timings while PC enthusiasts utilize the BIOS to ensure system stability and security.