Movie Maker convert to Movie File problem

I have spent over a hundred hours creating and editing a Windows Movie Maker project and am ready to save it as a movie file. However, in attempting to do this MM does not recognize where my files that were imported and used are.

I have not deleted or moved any of the files I imported. My project is not lost as it is still there and workable as a project. How can I convert it to a movie file with MM seems to not be able to locate the files in the project on my computer? I know Adobe Illustrator has a way to locate files that have been moved, but I don't see any options for that in MM. Help!

I read a thread where this happened to someone because they deleted temporary files/folders in a system restore, but they lost even their project. I have performed maintainance tasks on my computer, but the project and all files are still visible and working in MM. Not sure if this helps diagnose anything.