SL won't 'load'

I recently updatd to Windows Xp Pro Sp2 and now whenever I click to get into SL the box with the hand comes up and says "Loading" then goes away and nothing happens, however it says it's running in processes. I've tried uninstalling and reinstanlling and even restarting my computer and nothing work.

Note, SL was working just fine on my old Win2k before the upgrade.