Game Freezes and Buzzes for short duration while playing LoL

I have a rather unusual problem. I run my Windows 7 (64 bit) through my Mac computer using bootcamp so I can play games on Windows (never will I buy a mac again). Outside of my friends making fun of me, I have never had *any* problems running Windows on my Mac. In fact, my computer works even better while running Windows and I hardly (if ever) boot up my mac OS. Recently I moved into a new apartment in the city, where the houses are much older than the suburb I was living in. My computer will sometimes buzz through the speakers and my screen will freeze, but then everything goes back to normal. I get no error messages, the screen simply freezes. Two important things to note:

1. This doesn't happen every day, and when it does it doesn't happen more then 2 times.
2. I am inclined to think this is an electrical problem. Why? My computer literally started doing this the day I moved into the apartment. I never had this problem before now. My apartment only has 2-pronged outlets, so I had to connect it to a converter.
3. During my first few days there, I would run my computer through an extension cord, that would plug into the 2-3 prong converter. When I had stopped using the extension cord, I thought I had actually fixed this problem. But, as I said, it just happens less frequently now.
4. My video card is up-to-date
5. I only notice this when I play games on my computer and at no other time. I play League of Legends.

Well, I am going to have to say that you may be right, that it is an electrical problem and it has more to do with low wattage at some peak times than it does with your computer or setup.

Are you running a UPS as well? if not, perhaps investing in one might solve your problems... having one of those so called "Surge Protectors" has never been my thing or they have never really work well for me. Battery Backups have save me quiet a few times as in Miami we are never short of lightning or thunders.