Well, I have no replies above but maybe everyone's enjoying their Easter break while I am having to deal with DVD/PC problems Anyways, I have resolved the above issue. In case anyone else comes across this and needs help like me: here's what I did... I uninstalled PowerDVD, WinDVD and the other players that I had tried to get to work. I then downloaded and installed Xp Codecs Pack 1.2.0 which was available on the website www.videohelp.com or you can just goggle and find it. Once I had installed the codecs package, NEro Showtime which I had installed with NeroVision began to play sound. So did WMP10. When I clicked on the info button in WMP I could see a plug-in called AC3 which gave me all sorts of controls and must have been what was needed to get sound.
So, all in all, if you dont get sound out of your DVD player but have sound working on every other aspect on your system, you need codecs--it's a software issue. I have also read somewhere that to re-install your DVD player could've made it work as well but I just installed the XP codecs package which I figured would come in handy anyways later for any other media.