Hi, I am not 100% sure if this is a software or hardware issue but are more inclined to believe its hardware so that is why I'm posting it here. Basically here is my build: Core i5 750 (lga 1156) 8gb ram gtx 750ti Asus p7p55 lx motherboard. I recently upgraded the GPU and Ram. At first the PC performed miles better than before and I also changed the thermal paste. The problem started 4 to 5 days after the changes. The PC suddenly started shutting off and restarting. Here is what I've tried so far: 1. I thought maybe the problem was the IO shield but I removed the motherboard and again installed it making sure the contacts align correctly. 2. I then thought the problem could be the power supply but I also changed that with a brand new one (thermaltake toughpower 750). I don't understand what the problem could be. I feel like something could be short circuiting but can't narrow it down. I have checked the normal culprits but it didn't solve it. Previously it allowed me to boot into windows and I checked in the event viewer and found nothing helpful as to the cause of the shutdowns. It was random: sometimes it would shutdown after 2 min or sometimes after 15 or 20 min. But now its barely able to boot till the windows login screen and usually restarts before that. I am really confused as to what could be the cause of the issue. The PC was finally performing well and I hoped to get 1 or 2 years use out of it. Can anybody here suggest any solutions? If it would be helpful, I can post a 1 to 2 min video I made in which it restarts a couple of times.