I have never overclocked my PC, but I have come to the conclusion that it was my MB. A friend of mine had the same exact model MB as I had, and he recently purchased a new MB. So he gave me his old one (same model as mine) and I switched them out. My PC has never turned off since then. But over a period of time I have done the same things you have said, that is how I know it was the MB. Thank you very much for the advice too. We think alike.