IE crashes when trying to watch a video on the net

Everytime I try to watch a video on a website, it crashes. When I send the report in, it says that there is a problem with the xvid codec and it suggests to uninstall and re-install it. I follow the suggestions but my IE still crashes. I’ve tried to update my xvid codecs but I’m not too sure on how to install the lib. files. Could someone help me out?