To avoid reboots, see picture. If u are in a reboot loop sequence see picture and un-mark automatically restart at errors.
It creates a error dump file but Ive always had this unmarked regardless of errors and never completely crashed the PC (since 2006).
To the problem, my guess its OS or HDD related.
If u had cpu issues windows would have problem start at all and u would hear (or not hear) certain parts in the PC isnt spinning or working, if gpu, there would be a either black screen or windows basic screen would be showing the desktop i.e very big icons and like 800x600 resolution.