Audio out on DVD but not CD

[cableman]

My dvd player attached to my television went out so I wanted to watch regular dvd's on my computer. The computer is Dell pentium 4 3.0 with 2 gig ram. I have recently installed a new LG brand drive which is a combo cd/dvd/rw.

I installed all the software that came with the drive and it came with "power dvd" which I let it use as default but when I played the dvd I get picture only no sound. I put in a Sheryl Crow music cd and it played it fine.

Can someone please tell me what I need to do. I have a couple of older audio cards that will fit an empty slot in the computer but I would rather fix it otherwise. Everything else is working, I hope this is something simple. All my movies downloaded on the hard drive play fine.

Can someone please help me fix this.

 

[cableman]

Update problem

To update what I have done. I have successfully installed an audio card and it is now working. I went in to bios and changed it to auto. So if a card is in it should go to it and if a card is not in then it should go to the inboard audio. The only thing is that it didn't do anything at all to fix my problem. My problem stays exactly the same except now I have a sound card installed with the cable from cd/dvd to card.

 

[ucould2]

Have you downloaded the latest video codecs here are three, of these player types there are others though.
DivX from here

or Windows Media Player from here

or Apple Quicktime from here