What is BIOS?
BIOS (basic input / output system) is basically the “software” the computer uses for it’s most basic operations (accessing memory, disks, processors, etc.). This “software” is built into the computer’s motherboard, so don’t worry about losing it if your hard drive crashes.
Note that these are NOT Windows settings, these are the “core” settings for your computer. You normally can get at them by pressing the DEL key a few seconds after you turn your computer on (this can vary from machine to machine though).
Most BIOS setups allow you to configure hard drive parameters, set the time, type of floppy disk drives, memory timing, and so on. It’s probably an area that’s best left alone unless you are an experienced computer user. I’ve seen more than one computer that was rendered useless from tampering with these settings.