The best way to reset the BIOS is to unplug the power cable, Drain the computer system from any juice that is still stored in the PSU and mainboard capacitors by pressing and holding the Power button (for 10-20 seconds). Remove the CMOS battery, again hold the Power button (for 10-20 seconds). You should find a jumper labelled Clear CMOS (or CLR_CMOS, or something in similar), set the jumper as described on the manual of the website. leave it for 1min. and change the Jumper to its original state (by not doing so you may damage the mainboard, because of damaging the BIOS chip itself or the software image). After that, put back the CMOS battery in its place, plug the power cable back, and turn on the PC. This should reset the BIOS back to...