I uploaded several videos successfully into Movie Maker and proceeded to edit them without difficulty for the next hour or so.  I then saved the project as a project as it was not complete.  Shortly thereafter, I reopened the project to find all the videos I had uploaded had no sound nor video.  All the pictures and text still appear and the videos take up space in the right hand editing display, however, when playing through it on the left hand preview screen, the screen is completely black and their is no audio.

Since then, I have attempted to replicate this error without success, even uploading the same videos to a new project.  I am at a loss as to how I may reclaim my Movie Maker project or how the error even occurred.  Any and all feedback would be helpful.