I still had problems after reinstalling Win 7. I decided to run memtest to see if that showed any errors. It was only showing 12GB. One stick was only partially inserted. The Sabertooth X79 makes it hard to see if it's fully inserted. Now 16GB shows up. Let's see if that was causing me problems... I ha pulled the RAM, video card and sound card out to do some cleaning not long before the problems started. If not, I'll run memtest for a while. If nothing shows up, I'm going to think something is going on with my PSU or video card.