I've been working on a video for my sons 1st birthday in two weeks!!  I haven't had any issues until I went to pull up my video to work on it today. 

I'll admit, I'm not very computer savvy.  My first 8 photos are showing, all my music files are there, and the videos I put in are showing, but ALL my other photos have a yellow triangle with a ! in it and when I click on the icon it says that the file is missing.  Nothing happens when I select "find."

Any suggestions??!  I am going to be devastated if I have to start all over again.  And if I do, how to I make sure this doesn't happen again?

Running Windows 8 and my Movie Maker is Version 2012