How to Reset (clear) your BIOS

To clear the CMOS is to short the "CLEAR CMOS" jumper on your motherboard, assuming you have one as most of the motherboards do.

Clearing CMOS using the jumper (clear jumper)

• Turn off your computer completely.
• Open your computer and look around your motherboard for a jumper labeled ClR_ CMOS or CLRTC . These jumpers are usually located near the BIOS chip itself or near the CMOS battery .
• Remove the jumper from pin 1 and 2 and place it on pin 2 and 3, wait for two or three minutes, then return the jumper to its original position. All parameters of Bios will be deleted.
• At times in some motherboard by removing the battery also clears the CMOS. 
•  It is possible that a message “Checksum Error” appears at the start of your system. You can simply try to restart. If the message persists, load the default settings of your Bios (Press Del, F1 or F2 to enter Bios setup and press “Load Optimized Defaults”).