Marziie :
James Mason :
PSU dying maybe.
What does Event Viewer say in the System Log around the time it happened? (don't paste the whole thing)
Is this it ?
Critical - Kernel-Power it says :
"The system has rebooted without cleanly shutting down first. This error could be caused if the system stopped responding, crashed, or lost power unexpectedly."
I did guess it was the PSU. But I'm trying to see if it's something else first since I got this PC like 6 months ago from a PC shop and I had them assemble it with new parts.
New =/= good.
Shops (prebuilts) typically will use the cheapest (and thus lowest) quality PSUs to save money, but it usually results in stuff like this.
That error does describe exactly what happened, but it can generate that error from a great list of things, but they're all virtually related to power. Unless you unplugged it accidentally, or had a blackout/brownout or blew a fuse or had a power surge (hence why surge protectors are important) then it means your PSU crapped out on you.
If you can get the problem to repeat (do tutorial/practice or co-op games or something to test) then you can narrow it down.