I have 8 or 9 Movie Maker Projects that I was currently working on. Windows 7. All of these projects had music files (.m4a,) that worked flawlessly. No issues at all. Well, after a few months break, I went back to these projects to check in and complete. Now every .m4a song has a warning that states that Movie Maker cannot read any of the .m4a files. I spent many hours with Microsoft with multiple techs on my computer but none of them could figure it out, (it seemed each were not really versed on Movie Maker.) Their advice was to convert every music file. Using Itunes for pulling music, this is extremely problematic. It seems to me there is a simple solution or fix, if only...I tried to re download Essentials but no change. Help!!

Craig