I was playing my .avi movies with no problem from my MyBook Essential drive in a folder on the MBE. I decided to backup my desktop computer onto the MBE and it is in a separate folder. Since I did this none of my movies will play saying they are in an unsupported format. These movies were only stored on the external drive and not on my computer so there are no duplicate movie files. When I have the MBE connected to my computer the movies play no problem.
What do I do to make them play?