How to Enter the BIOS in Windows XP Professionalby Christopher Hanson
The BIOS (basic input/output system) is a piece of firmware below the operating system. The BIOS is the firmware used to monitor and edit the CMOS (Complementary metal-oxide-semiconductor) settings. Depending on the make and model of the computer, the BIOS will have a different access key.
Turn on your computer.
Watch the bottom of the screen. There will be a message that says "Press a button to enter setup." On most systems capable of operating Windows XP Professional, the access key will be F1, F2, F10, DEL or ESC.
Press the access key.
Enter the password if one is set. By default, there will be no password.
- bios chip image by Nikolay Okhitin from Fotolia.com