PC is randomly shutting down

So my PC has started shutting off every now and then for a split second then starting back up instantly. I've been monitoring the temps and they arent very high, my PC is warm but not enough to crash it or anything. I don't know if something in my PC is short-circuiting and shutting it down, or if it's the electrical wiring in the house I'm at now. It's a pretty old house, built in the 60s everything in it is original to the house so I wasn't sure if maybe the wiring might be old/shitty in the basement I'm in.

 

Anyone else have more ideas/help? 

What are you doing whenever it shuts down? Just random things?

It's the computer. It has to be if none of your other electrical supplies are going crazy. How long have you had the computer? Have you taken it to an electronic store to have it tested?