How much space is on the hard drive? Have you defragmented recently? If not try defraggler. Same company that makes Ccleaner.
Don't expect to get more than about 15 FPS out of that laptop. It's not meant to game. It's just capable of gaming. Chances are there's not too much more you can do. If it's playable, even if it can be laggy at times, then I wouldn't expect too much more than that.