Use prime95 to stress your CPU and if it does give you a blue screen that might be it. Also try taking out 1 stick of ram and check with each one in if you still get a blue screen. If you could take a picture or post what it says on that blue screen that might help also.(personally i would start with a new PSU)
I have tried taking out the ram and seeing which one works etc, and it didn't help. I found a temporary fix by installing older drivers, but now the problem is back. Gonna try get a picture of the BSOD.