The MP3 you are trying to play either uses compressed ID3 headers or an unsynchronized ID3 header or otherwise has to-WMP-unintrepretable ID3v2 data, which the player does not support for security reasons. If it has unsynchronized ID3 headers, then the Q814129 QFE will allow these files to play back. Otherwise – if that does not work -, you would need to use a tag editing software program to eliminate the compressed ID3 information. In some cases, you will just need to remove the Comments section, in others you’ll need to delete all ID3 tagging on the file. Alternatively, the file could be played in most other players. A quick way to clean up the file is to open the file up in WinAMP 2.x, right-click on the file in the Playlist window, choose “File Info” and uncheck ID3v1 tag and ID3v2 tag, then click Update. The file should then work fine in WMP. Alternatively, if you want to use a Tool to do this, you can use the Advanced WMA Workshop. In some cases, people have gotten error 0xc00d11