Plugin missing

I’m trying to get started learning Unity by reading the visual tutorials but for all of them it says that a plug in is missing. What plug in do I need in order to watch the video tutorials?

Thts a quicktime plugin, just download the latest version of quicktime to see them. and dont respond to someones question with an ansswer, thats what comments are for

Any of these. Not a single one of them works, all say I need a plug in but nothing else.

http://unity3d.com/support/documentation/video/