I assume that the class animation in question is one created by Thomas King. If so, you need to have the Microsoft .Net framework installed on your computer. If you use the Windows Update function from your Start Menu, .Net framework should be listed as one of the optional upgrades for your system.
EDIT:
If you still have trouble installing this class animation, go here:
http://p206.ezboard.com/ftranscende...icID=47.to pic