If you're really that worried about being able to play games on your PC, just get an Alienware computer and forget about the whole mess. Super expensive, but super high stats. You'll be gaming with it for a very long time. Of course, I have a an old computer (2004, I think) that still runs XP and has less than optimal stats (even for a computer of that day) and I can still play most games. I think the bane of my gaming was when I tried to play Oblivion; that was the first game that refused to play, not because of my specs, but simply because I wasn't using a specific brand GPU.

Now, I don't expect you to go out and buy a crappy computer like mine, but I would say that you shouldn't need to worry so much about it at the moment. You really can't go wrong unless you purposely get a very old machine for the price like I did ($280 for PC).