Okay. We now have the info (but don't hold your breath!
)
Because a Stop error BugcheckCode is zero, and your PowerButtunTimestamp is zero, you are seeing
Scenario #3.
Unfortunately this means ... you have NO INFORMATION AVAILABLE to tell you what's going wrong. I.e. It says "your computer is shutting down/rebooting for "unknown reasons."
(I TOLD you not to hold your breath! Good old Windoze! Tell us something we DON'T already know! 
)Furthermore the provide a laundry list of things to try/disable to try to isolate the problem, most of which we've already gone through!
You can, however, review them and try modifying them ONE AT A TIME (while over time long enough to see the problem still occur AT LEAST THREE TIMES yet, after the ONE change to your system was made.)
DO NOT TRY THEIR SUGGESTION #5!!! (Unless you want to "nuke & pave" your system.... 
)Finally: You might give the steps that disable auto-restart on your machine to see if you get a BugcheckCode value that's valid, but it's a VERY long shot. (But if nothing comes from it you can easily follow the instructions to re-enable the "Automatically restart" check box.)
Long story short: We didn't really learn that much from Windows about your problem.
...Back to square "x" I guess. Sorry...
