After an hour or so of normal, or even no use, windows 8.1 becomes unresponsive. I can move the mouse around, but when I click on something, it hangs and the a few minutes later frees up, the freezes again. When I boot into safe mode I don't have the problem. I have done multiple scans with various software, and with Microsoft diagnoses software. All have found and fixed errors, but didn't fix the problem. My hard drive activity shows maxed out constantly once the problem starts, but not much data being transfered. Anyone have any ideas?