so maybe you solved the problem by yourself
it can have to do with overheating problems o
And also if no BSOD (Blue Screen OF Death) is shown is that because its a hardware problem....
that have happened to me before (your problem)
and in my case was a memory problem....
anyway send the report to microsoft and see what they say, some times they send some valuable info, others you are pure and simply ignored
any way if your pc case has low ventilation try to open it and work with the pc to see if the problem resides in the heat (this isnt a 100% sure test)