Sounds like you are missing a codec to play DVD. Can you see the files on the DVD when you use Windows Explorer? If you can, then install a DVD player like Power DVD to play DVD movies.
There are some other players out there that do well, try VLC media player and see if that works alright. Or, there should be a player that came with the drive. And when you say "reading it", do you mean that it wouldn't recognize the disc? I mean, can you not open any DVD, even a data one? If that's so, it could be faulty hardware in the drive.