what he said..
the usual reason for updating the BIOS is to have new CPU support or something along those lines. but i too have been known to update for no apparent reason..
what you would need to do is go to your computer or mobo manfacturers website, which i would assume based on your sig is Gateway, and find a BIOS update for your machine..you can then download a program that will allow you to update or "flash" your BIOS in Windows itself, but i never do that so i cant tell you which program to use...now onto the way i use.
create a startup floppy disk, then make sure the update file you download is an executable file of some sort, and then put it on the startup disk you just made, set the PC to boot from floppy first, then boot it up and run the executable file from the A: prompt...if you need anymore help just ask around.