get picture but no sound

I use xp pro and netscape 7.2.
When viewing a lesson from cnet i get the video but no sound. I can play music and movies that i have downloaded
just fine. Can anybody give me a fix ror this problem?
here is link to one of them
http://vhs-dvd-movies.workshops.help.com/lesson-3/

 

I have seen an identical question on this matter. The link does not get me anywhere, and I get an Enroll button, saying

. I am not interested in enrolling, so I can't check it out. Can't you contact CNET?

 

It may be that you need updated audio CODECs. If it opens in Windows Media Player and you are running WMP version 8, you could upgrade to version 10. The same if it opens in another player. You could also check the media player's website for updated CODECs for download.

Also check for a suggested media player when you start downloading/streaming.

Matt