User Accounts: Blank?

So im having this very strange problem over here… :expressionless: I am running XP, and when I try and get into User Accounts, (in the control panel, or just click the display pic in the start menu) The window pops up, but there is only a taskbar, and white screen where all the options should be.

I have tried restarting and all that fun stuff, but no dice.

Any suggestions?