The ASUS P5KC is a computer motherboard that supports Intel LGA775 processors such as the Core 2 Duo. The P5KC features overclocking options that can enable users to run certain processors at speeds higher than they are rated, and when you adjust the motherboard speed to overclock the processor, that change is stored in the motherboard Basic Input/Output System, or BIOS, configuration. When overclocking with a motherboard such as the P5KC, it is possible to configure the processor to run at a speed higher than what it is able to support. If you have made this or another change resulting in the P5KC being unable to boot, you will need to reset the BIOS to its original configuration to resolve the issue.
Shut your computer down and disconnect each cable. Bring the computer chassis to a work surface, remove the cover and place the chassis on its side so that you can access the P5KC motherboard on the inside.
Locate the round silver-coloured battery on the P5KC and lift it out of its socket. If you are unable to remove the battery with your fingers, you can pry it out of the socket gently with a non-conductive tool such as a craft stick.
Locate the jumper marked "CLRTC" on the motherboard. The jumper is an array of small metal pins, with two of the pins joined by a plastic cap. The CLRTC jumper is on the side of the motherboard opposite the processor.
Move the plastic cap from the pins numbered "1" and "2" to the pins numbered "2" and "3."
Count to 10 slowly and move the plastic cap back to pins "1" and "2."
Place the round battery back into its socket with the positive side facing up. The positive side is etched with a plus sign.
Replace the chassis cover and return the computer to its original position.
If you have made any changes to the BIOS configuration of the ASUS P5KC, you will need to re-enter those settings after resetting the BIOS. Press the "Delete" key immediately after turning the computer on to re-enter the BIOS configuration.