The BIOS is the software interface between the CPU and the operating system. It runs a series of hardware tests when you turn on your computer, and it sets the configuration of the computer's memory and I/O devices.
This chapter has explained how the BIOS works and how to change the options in the BIOS Settings Utility. It also explains how to restore the BIOS to its default settings, how to replace the battery that keeps the CMOS memory alive, and how to update the BIOS software.