Computer restarted with no warning

For some reason, while I was on a voice call and playing Minecraft, all of a sudden, the computer forced itself off and started up again by itself. I have ran CHKDSK with no errors, and scanned with both Malwarebytes and AVAST and no viruses and malware was found. My power wasn't interrupted either as other things plugged in the surge protector were still powered. I have checked Event Viewer and it lists this as an unexpected shutdown. My CPU temperature is fine too. Is this just something random that happened for no explainable reason?

Ok, I have done 1, 4, 5, 7, 8, 9, 10, 11, 12, 13, 14, 15, 17. I can't do 2 because I am using too much electricity already, don't have time for 3, don't know where to get canned air in Korea for 4, will do 6 if problem keeps on happening, I don't know if there is an alternative way to do 16 for Windows 8, and 18 and 19 does not seem necessary. I have checked the Dell website for all driver updates and all of my drivers are current. I have checked inside the case through the many vents and there is no dust clogging it. If I find have any more problems, I will post about it here. For now, I think this is enough and all I can do for troubleshooting right at this moment. Thanks Greg for helping me.

The optional updates are a bluetooth driver and the update KB2995388. Important updates were already installed automatically on Patch Tuesday.

Wait, if there is no WEI in Windows 8, how do I access the performance log?

Could be because the power from your wall socket is having a problem, the cable from the wall socket to the power supply and maybe the power supply.

Well, so far, the computer is running fine. The wall outlet should be working correct as other things on the surge protectors were working the moment the computer restarted. The surge protector should be working correct too for the same reason. I think it was some kind of software problem but now it is gone.