There are 2 ways you can reset your bios.
1. On the motherboard there is a small watch battery. Remove this battery along with the power cable from the power supply. Hold down the power button to fully discharge the system. Wait 2-3 minutes then reinstall the battery and plug in your system. Your reset is now complete
2. Some motherboards have a 3 pin jumper by the battery. Lets say that the jumper is on pins 2 and 3. Remove the jumper while the machine is OFF and place onto pins 1 and 2. Power on your machine for a minute. (Note: Your system will not POST). Shutdown your machine and put the jumper back to pins 2 and 3. Your reset is now complete