So my PC just blue screened and rebooted by itself whilst I was playing Black Ops 2 Zombies. It's the first time it's happened with this PC(I built it 5-6 months ago). So far I haven't had any problems. My PC hasn't been slow or crashed for any reason. I don't download malicious software, I do regular security scans, I haven't overclocked anything and I recently used CCleaner. I'm not sure what I could've done that harmed it. Recently however we had rolling blackouts and my PC shut off about 3 times. I'm not sure if that's the problem. But basically what I want to know is what could've caused it and do I have to worry?