Jwenting From Netherlands, joined Apr 2001, 10213 posts, RR: 20 Reply 1, posted (10 years 2 months 6 days 18 hours ago) and read 8992 times:
there's nothing to help.
For one it's not needed (your performance is quite enough), for another your machine isn't up to it.
Get more RAM (increase to about a Gigabyte), a better videocard (and don't get suckered into a lowend card, a GF FX with a minimum of 128 MB but better 256MB is recommended), and you might get more fps.
But always remember: FPS == F***ed up Performance Specifier!
What's far more important is fluidity combined with good visuals.