Why does my sound work but no video show up? Typically your computer will already have this MPEG-2 DVD Decoder plug in installed. This problem is pretty common after you format your computer and reinstall the operating system.
In order to view the DVD video playback you need to have a decoder installed. Typically the sound/audio will work but the screen is black or blank.
You can find the Microsoft article here that will refer you to several DVD Decoder providers.
For example: Roxio, Cyberlink, interVideo, and Nvidia all provide this software.
Typically these software plug-ins run about $15 and once you download it be sure to save it in case you need to format and reinstall Windows again.