The BIOS (Basic Input/Output System) if firmware (located on a chip on the
motherboard) which controls how the computer interfaces with various
peripherals and other parts of the motherboard. It is totally separate from
the operating system (XP in your case) and all other hardware (it works with
the hardware to enable data transfer). Flashing the BIOS is simply updating
the program in the firmware. If the BIOS is flashed improperly or with the
wrong code the motherboard will be useless.
Steps to flash the BIOS is generally given in detail with the BIOS patch
that you download from the internet.
Steps to take anytime you are doing major configuration work (and flashing
the BIOS is major configuration work:
1. Backup all data (Ghost image of the hard drives is probably best)
2. Create any rescue disk or recovery disk for the operating system that
would be needed to recover the os (XP's CD is bootable and will suffice).
3. Purchase an uninterruptable power supply, make sure it is fully
charged and the computer is plugged into it before flashing the BIOS (If the
power goes out in the middle of the flash, you have an expensive paper
weight.)
4. Create a bootable floppy disk by formatting a floppy in Windows
Explorer and copy the system files to it if your flash program requires it.
Test the floppy to see if you can actually boot with the disk.
5. Move or create the flash program on the bootable floppy disk from step
4 if the flash program requires it.
6. If the flash program allows it, create a backup copy of the current
program on the BIOS.
7. After the flash of the BIOS, reboot the system and be prepared for the
OS to have to go through a complete "new hardware found" sequence. (Happens
some times as the BIOS will have different parameters.)
Check these web sites for additional information
http://www.wimsbios.com/
http://www.pcguide.com/ref/mbsys/bios/comp_Flash.htm
http://www.tyan.com/support/html/how_to_flash.html - this last one is for a
particular bios but it does give general instructions. Follow the
directions for your BIOS.