reset it. If this is a desktop computer, not a laptop, you can reset the CMOS by

1) moving the jumper block to the opposite two pins of the 3 pin CMOS header on the motherboard, then move it back to its original posititon.
2) remove the CMOS battery for an hour or two, then place it back

Both scenarios reset the Bios to its defaults, sans password. Laptops are another ball of wax.