Audio Codec ?

My friend sent me a link to a avi video , and it opend in windows media player and it started to search for a codec to download, normally its a video codec but to my amazement it was a audio codec, and it couldnt find it !

So what I am asking is, what audio codecs are out there to be downloaded that I could be missing ?

i tryed updateing my divx and i tryed then opening it in divx and got a error about not having a codec and said this ...

Audio Data: Tag 8192

try googling gspot and install that. It finds out what specific codec you need.