Quick Time Pro Video Not Working

I am trying to play a .mov file in Quick Time Pro and the video is not showing up. The audio plays just fine. I initially got an error that took me to a webpage to download a plugin for QT, but I have no idea which one to download. Is there a specific one I need to get?

Just get perian at Perian - The swiss-army knife of QuickTime® components. It should solve your problem.

Okay, just downloaded and installed it. Is it supposed to just automatically work?

Perian didn't work for me in this case, unless I am doing something wrong.

Go to System Preferences and look at the bottom under "Other". Perian should be there. You might need to restart the computer to get it to work, I don't remember. Worse come to worse, you could always get conversion software like HandBrake and play it through a usable format.