Have you tried using a new CMOS battery? If not, try using a new one. Try to reset your BIOS first. Boot up then set your BIOS and save. Check if you still receive the message. If not, try restarting your computer again..
If you are no longer getting the message, turn off your computer for 3-5 minutes. Turn on your computer, then check if you are still going to receive the message. If you are no longer getting the message, your problem has been resolved... :grin:
If the problem persists, try resetting your processor, then try again. If all fails, there is something wrong with your mobo. Hope this helps...