When you open Windows Movie Maker, source files are sometimes missing in the Collections pane. Windows Movie Maker collections and projects do not really contain the media files that you work with; rather, projects and collections only reference the digital media files wherever they are located, such as on a CD, hard disk, removable media, or shared network location.
Some of the reasons why clips might be missing in Windows Movie Maker include the following:
•
The CD, hard disk, removable media, or network location that Windows Movie Maker uses to reference the file was removed or is no longer available.