Start Rhino in Safe Mode: Windows start menu, type in ‘Rhinoceros’ and look for the ‘Rhinoceros in Safe Mode’ entry.
Does that work?
Are you running plain Rhino or are you using non-default plug-ins? If so, which ones?
What version and service reelase of Rhino?
What is the video card on the machine, and are the drivers up to date?
Is Windows full up to date?
Do you use multiple or external monitors? If so does it help to disconnect these?