System I7 3770 not oc'd 16 gig ram Gigabyte Motherboard GTX 660 Power Supply is a Corsair 700 Watt only about a year and a half old. I am having trouble figuring out what may be causing Windows 8.1 to crash. It seems that it is fixed and then it isn't. Here is what occurred: 1. Never had any issues with Windows 8. Updated to 8.1 around October 21st. 2. I didn't have any crashing with BF4 beta ( it was running on just standard Windows. 8) 3. Upgraded to 8.1 because it promised more performance. 4. Started to have hard crashes-system would just simply power off and restart mostly when a level was loading not during actual gameplay of Bf4. 5. Normally I would say that is a power supply issue. I purchased a new one over a week ago. I didn't install it yet because I wasn't sure if that was the issue Here is the weird thing. When I did a system restore after that started happening I wasn't having any crashes at all. I would really be taxing the system on purpose I.e running two virus scans while playing bf4. I literally joined over 130 servers and could not recreate the crash. I also did the system torture test with no issues. I did the system ram test and it was fine. I am not sure if the crashes were related to Malware which I found on my system Tonight it crashed twice. I tried to do a system restore and all of my system restore points were gone. But that will be fixed tomorrow. The big question is what could be causing the crashes? It seemed hardware related at first, but it seemingly was fixed by software.