BIOS & CMOS

From ITS Wiki - Information Technology Services - University of Rhode Island

Basic Input/Output System (BIOS)

The BIOS runs at the startup sequence where it configures devices (including keyboard, display screen, disk drives, serial communications) and then boots the operating system. The function of the BIOS is so vital that the information on the BIOS is stored on a chip separate from the hard drive to protect it from potential crashes.

To access the BIOS interface, look for instructions as soon as the computer is turned on. Many systems require users to press the F2, F8, F10, or F12 key immediately after turning on the computer. Once the interface loads, users can change the system date and time, alter the boot sequence, and manage hardware components.

It is often necessary to edit the boot sequence to allow for booting from a Live operating system, such as a CD or DVD, or when installing an operating system for the first time. In that case, the CD/DVD option should be set at the top of the sequence and the corresponding media should be inserted before boot.

Complimentary Metal Oxide Semiconductor (CMOS)

A chip mounted on the motherboard of a computer that runs the BIOS using extremely small amounts of energy from a battery also mounted on the motherboard.