Larry is having issues with his Windows 10 machine restarting. It physically shuts down and restarts. Leo says he has a hunch that the power supply is failing and it is causing a restart. It's definitely not a software issue. It may also be heat-related. If it happens under "load," and your fans aren't moving air enough, that could be it. Heat can also be caused if your computer's insides are blanketed with dust. That can cause the computer to overheat as well.
But the likely culprit is the power supply.