That score seems a wee bit low. I have quite a powerfull pc and the highest i got was 1112, however I am going to buy a new radeon 9800xt so that should send it up to 3-4000.
The best way to improve it is
a/ close every program u can think of before running it eg virus checker, word find fast, the lot
b/go your graphics card homepage and download 2 things, the newest drivers plus a tweaker, this will allow you to adjust ure card setting .
c/ if u know how to, overclock ure processor
d/you can download a program which 'formats' ure ram. Run this prior to runnunig the test.
If u do all this, i bet ure score will get to at least 500