When i have been starting up my computer it hangs shortly after load, i went into safe mode and i put the power saving option to preformance and it boots fine. Although i have had some problems with stress testing and it fails(small fft's works but others crash). It also crashes when i render video's in Vegas and when i record using Camtasia I thought it could be the CPU overheating from a high load so i got a new HSF(Was stock before) and reapplied some thermal paste the problem is still occuring.
It would also hang when i reimaged installing windows 7(After first restart) so i was forced to use it on another computer and it installed fine. I then ran memtest from the ultimate boot cd and my Memory sticks all passed(4 2X gb sticks). I have also tried 2 PSU(750W and a 400W)
Im not sure what is causing this could anyone give me some suggestions where to look?