PC randomly restarts without warning

[Jydn]

A few weeks ago my pc randomly restarted without warning, and it didn’t say “restarting…” it just turned off as if I had held down the power button and then turned back on again. It usually does this about 3 times at random intervals ranging between 10 seconds and about 10 minutes, and then it’s fine. It usually fine for the next few days that I use my pc until it decides one day to start doing it again. Pls help I don’t know what is causing it because my computer doesn’t tell me. 
btw my pc has been fine for about a year before this started happening.

thanks 

[leclod]

One of the things you could do is what's in there : https://www.tomshardware.com/how-to/fix-windows-10-repair-install

Or the things he has tried :