The main menu will work fine, but when I get into the battle I get about 3 frames per minute. It just lags like crazy and the graphics get all screwed up.

For instance, I went in as a rebel sniper on Endor. The sniper was all yellowish and I saw big grids spinning in circles in the background.

I haven't changed my driver or hardware recently.

How do I make the game work?

P.S. I already tried reinstalling.

What are your computer specs? What Video Card are you using? Make sure your graphic drivers are updated.