iMovie 3: Has Generic Icon and Won‘t Open After Reinstalling Mac OS X

Symptom

iMovie does not open. Its icon looks like a generic application.

Solution

Use one of these solutions:

• Drag the iMovie application to the Trash, and use the Mac OS X installer to reinstall iMovie 3.
  
  or
  
• Install iMovie 3 separately. It can be installed from the iLife CD, or downloaded from the iMovie website (http://www.apple.com/imovie/).