Did it ever play DVDs?  What DVD Decoder is installed?

Not really sure. Have never played a movie in it until now, but had a picture dvd from vacation that played.

To play a commercial DVD movie, you need to have DVD Decoder software.  You can try
VLC Media Player here to see if it will work and help determine if there is another
reason the DVDs will not play .................

http://www.videolan.org/vlc/