I've had this happen multiple times. I'm 100% sure this hasn't been answered so don't tell me this is a common problem. Here's what happened, got a new computer, I took my gpu from my old PC and popped it in my new one everything was fine. One day I needed my old PC and it wouldn't boot properly. It kept saying it was diagnosing my PC and in the advanced options menu I couldn't do anything. So I simply reinstalled windows and now it's back to normal. On my new computer this happened 3 times all from different causes. 1st was it crashed. My PC just completely crashed and it did the boot loop so I simply reinstalled windows like before, Done. Did it again one day when I was gonna get a new gpu I was removing excess cables since they were taking up room and they were NOT plugged into ANYTHING. they did nothing. And when I powered it on, it started working normally and then it crashed and did the loop AGAIN. I got over it reinstalled windows and managed to find another key laying around. Here we are now, I was selling my old PC to someone and I was including my gpu as I was going to replace it with the money I got from selling my old PC. He bailed and I ended up putting it back in my PC since I wanted to use it again. When I booted it up, got the same glitch. I figured this would happen so I had created a restore point which my PC seems to think does not exist. Nothing else is working and I know for a fact, nothing is wrong with my PC. All hardware works there shouldn't be anything wrong at all. My first thought that might have been causing this was my storage. But then I remembered these are the same drives I used before and they worked fine then so it can't be them. My friend suggested something might be wrong with the gpu itself and that's what's causing this but I find that hard to believe. So I believe it may be because of the motherboard. That's the only thing I can think of. My PC specs are i7 950 24 gb ddr3 ram asus x58 sabertooth mobo 1tb hdd 128gb ssd and windows 10 64 bit. If anyone might know the reason for this I'd appreciate your Intel.