Plug and Play configuration error at start up

I have get Plug and Play Configuration Error  f1 to cont. f12 for setup utility...No new hardware or downloads installed ..has been about 3 weeks, most times it will not even load up... did all the unplug everything stuff...pressed all the alt e and alt f stimutanously stuff still have problems....only way working is unplugged everything over night and now up but still error message but at least this time! I can actually use pc till the next time it is rebooted...PLEASE HELP!!!!