I am trying to create a new project in Movie Maker 2012 using Windows 8.1 and when I try to add a video that is on a disk in the DVD drive, in a VOB format, it is only bringing in the sound.  The video is just a black screen.  When I search for other videos on my computer it is able to properly read in the MP4 files. There are no copyright problems as this was shot with a videocam.  What's the problem and how do I fix it?