NO SOUND!!!!

what program are you using? can you give us a better description with more details?

XONAR DS

Launch the DVD while playing a music file.. If still your mentioned problem persists then the DVD playback program is faulty.. In case then you loose audio on both the music file and the DVD, then check out with your system volume properties.. May be a faulty program is causing it to go as low as 0 when a DVD is being launched..

Try a different program and see if the problem persists. VLC media player is good and free.

I ended up uninstalling the DVD in Device Manager, restarted and actually downloaded a different media player other than Windows Media Player. And lo and behold: I now have sound when I play a disc.

Dumb question: if you have a DVD R player, you need to install software to enable it to operate properly, correct? is that what Roxio, Nero, etc all do?

1. Yes. Without software like VLC or WMP, you would have no way to play it. If you mean driver, then you only need the driver for the DVD drive, which you already have. If you mean a codec or something, WMP and VLC and all other programs already have that.
2. No. They are programs. Nero is great for burning DVDs so they can be viewed on a regular DVD player.