If you have audio files encoded with FLAC, which the media player can not play (look for the codecs, but then moves to the next song), try this package Illiminable .
download, close Windows Media Player, install the package, from now on should also read the FLAC, Ogg Vorbis, Speex and Theora.
I've tested on Windws WMPlayer 11 and XP Pro x64, the better.
