I suspect you have sound working in other applications. I use WMP 10. In the lower left corner area you should find a Mute button and a Volume control slide. Turn the Mute off; ie. Sound On. Run the slider up on the Volume control. Hopefully, this should work for you. The Mute button is easy to overlook. Otherwise, a deeper exam will be required.
The mute button is not turned off. It's still not playing. This is driving me nuts. Any other suggestions would be greatly appreciated.
I mean the mute button is turned off. It is turned off. The volume is up, and everything else works fine - MP3s, MPEGs, WAVs, etc.
WMP does not play DVDs all by itself. It needs a plugin to work correctly. Do you have one installed? Check at the Microsoft site for info regarding DVD plugins.
There might be a free one, but I am not aware of any. Try Google. I got NVDVD with my video card. Does that count as "free"? = If you have a full Nero, it has "ShowTime" which is able to play dvds all by itself.