I had a suspicion you were a mac user (using QT player.) There's a few techniques. One is to select a video file, command i (or go to File menu & choose Get info), then change the Open with to VLC. And then click the Change All. Another technique is to Control-click the video file & choose VLC. I think the other technique is better.

You should do this with AVI, divx, & perhaps also mpg/mpeg files. Although I use QT Player as default for mpeg 2 because I have pro with the mpeg 2 decoder/encoder.

To see details about how to do it, see http://www.gnutellaforums.com/showth...=default+video

There's an example for video. But there's also an example for iTunes with audio which shows the information window clearly.