I am having the exact same event occur. Every 15 minutes or so it causes a reboot with no BSOD (as there was technically no error). I would like to rectify this as soon as possible as it makes extended processes in-completable. *edit* I solved it! Apparently there was a x32 svchost running for some reason. Ending the process solved the issue an I may need to look further on WHY there was a x32 process running. Mayhaps some old software somewhere or a virus? In any case; my system looks clean.