Help please :(

Hi, I've had this computer that was built with ok parts that was able to play some games of mine back then, but now that I installed windows 7 64bit it can't play games like it used to. I have my monitor connected to my motherboard, and I just a bunch of games on steam that I'm dying to play, and so I'm just thinking of buying a  AMD A10-5800K Trinity, and a bit more of ram so that I can play my games till I am to afford to build my own. Is it a god idea to buy a bit of hardware just so I can play my games, and will it be able to play it without needing a graphics card?, and can I use it again in my first build. I don't really know what to do, so I thought I'd ask you guys. Also how much more ram should I get to play these games?...

These are my steam games:        *will the AMD A10-5800K Trinity be able to handle these games?*

Amnesia: The Dark Descent

Batman: Arkham City GOTY

Far Cry 3

Garry's Mod

Gotham City Imposters

Killing Floor

Portal 2

Team Fortress 2

The Elder Scrolls: Skyrim

Yes, You should be able to run those games at high settings with this APU. Although, trying to play more demanding games such as BF4, AC4 or Crysis 3, you my come into issues on any higher than medium settings. I do not know on those games exactly on average FPS, but given these benchmarks, I figure you'll probably be good.

What does your computer now have in it? And what's your current budget?

so I'd be fine just with this APU and a bit of Ram my computer would be able to handle it right?.. thank you I've been waiting just to be told my computer can handle it how much Ram should I get?

I... don't have a budget, but I'm willing to spend a bit on upgrading parts don't have much money to spend on a build working only part time, and going to school. I just want to play my games. What you think I should do?.