Plz help me, I love this game, but can't play :(

#1
Hello.
I can not understand why I'm there a little FPS game?
2 GHz processor, 2 GB RAM, which is not the case with the game?
I shook all versions, all the same!
When I turn in early mouse, screen freezes!
But under this screen, I hear as I go, I take the paper, and it feels like 60 fps!
Did not lag, but the screen is hung, and nothing I can do about it ..