I just install Vista Ultimate (DELL OEM) on my Inspiron 6400 with full latest drivers downloaded from DELL. But WMP11, Windows Media Centre and MediaDirect3 (all 3 of these soft) cannot play MP3 file. No message appear with Windows Media Centre and MD3. But an error message appear with WMP11 that "An audio codec is needed to play this file. To determine ..."

 

But other music player such as Winamp is OK. I try to install Vista Codec Package but in vail.

 

Anyone can help. Many thanks.