Make a video play with a push button on a device

I have a device shown here: [login to view URL] - it is like a mini computer with a tiny screen. When you push the button, a video plays. It works great, however, when I swap out the avi file to another avi file, it says invalid file format. I need this to work, whether it means using an entirely different file system, I don't know. I know this is super easy; just not sure how to do it myself. Here are the folders/files on the device: /PLAYLIST/[login to view URL] /PLAYLIST/dirplay.1 /PLAYLIST/nowplay.0 /PLAYLIST/nowplay.1 /PLAYLIST/nowplay.2 /System Volume Information/IndexerVolumeGuid /VIDEO/[login to view URL] [login to view URL]