Computer restarting from time to time

[Huntsman]

I'm expierencing a weird problem, my pc keeps restarting from time to time...... Regardless if im playing games or just simply browsing internet. It sometimes restarts few times in like 5-10 minutes period, but that is rare, and sometimes it doesnt restart at all, and sometimes it restarts like once or twice a day. My computer is clean of viruses and it doesnt seem like overheat problem either, because cooling works just fine.

[Devin]

Does it crash or just restart?
Are you sure all the components inside are secured adequately and not possibly shorting out?

[Huntsman]

Yea, i'm sure.

I guess its crashing, since it shuts down, stays that way for a second and then turns on again

[Gandalf]

Check the system error log.

[Huntsman]

Check the system error log.

And where am i supposed to find that?