Problem getting iMovie 9 tutorial to work

I'm trying to do my first movie project. I had a flip out camcorder that came with Divx software. All the video clips were AVI. I tried installing the Divx software but could not get the AVI clips to run.I tried importing my AVI clips into my iMovie but that didn't work; so, I tried running the iMovie tutorial and the following box:

“Divx Plus Web Player

The file you are trying to play has failed to finish downloading and can no longer play”

After the box went off all I got was the audio and no video.

I thought part of the problem might've been that when I installed the Divx software it became the default; so, I uninstalled the Divx and tried to run the iMovie tutorial again–same problem sound but no video. I have since got a better camcorder and want to download the movies but I don't know how to use iMovie as the tutorial will not work. Can you suggest how I can get the audio and video on the iMovie 9 tutorial to work

 

I'm not having much luck here no one seems to have a solution. Let's try this. Should I uninstall iMovie and then reinstall it?