Turn off your system, unplug the PSU, and flip the switch on the PSU. Consult your manual if you don't know where the CMOS jumper is. When you find it, there should be a pin cover on it over two of the three pins. With everything off, move the cover over to the other 2 pins and leave it there for 15 or 20 seconds. Then move the cover back to the original position. If your motherboard didn't come with this jumper, you can use a screw driver to jumper the two pins. You can check on Youtube. There are a couple videos showing you how to clear the CMOS. WARNING: The CMOS resets your bios so any overclock you had will be lost, unless you have it saved in your overclocking profiles.