I tried installing a new graphics card, but SK wasn't compatible with it. I removing and tried playing SK again, and got an error with the OpenGL libraries. I downloaded the drivers again. Then I managed to get the login screen without the "window" black part around the edges, when when I log in I get a black screen. I uninstalled the drivers and reinstalled them and the problem persists.
EDIT- Forgot to descirbe my dinosaur. Sorry. Graphics is integrated nVidia GeForce MX 4, Proccessor is AMD Athlon XP 2800+, 1.93GB RAM, windows XP professional SP3
Are you playing in a browser? Using the installed version of Spiral Knights? Playing through steam?
If other games work fine, it might be a thing with uninstalling spiral knights itself, and then reinstalling it.