Can't open WAV - need ACM Codec from Windows Media Player

This is Windows XP Media Center running with Windows Media Player 10. I use a program called WavePad to play my own created .WAV files. Recently I created one more such file but when I try playing it in WavePad it says: “Cannot open file need the required ACM Codec. Open this file in Media Player to automatically install the Codec.”

I have never faced this problem before. Do anyone have idea what has went wrong?

Well first of all your post is not enough to understand the problem. Can you tell what specific audio codec does this clip use?