Hi Zinx,
Issue reported: A Windows machine randomly restarting / crashing while playing random games.
Troubleshooting Scope: We first need to update Latest drivers and firmware/BIOS from the manufacturer's website compatible to motherboard in use. Then Install all Windows Updates including optional updates from Advanced options in Settings followed by a restart.
We then need to run a System file checker scan, DISM and Check disk scan /f /r /b, one after each restart using a command prompt with admin rights.
Please update with your findings!
Sincerely,
CK