Some audio players have their own settings for being the default to open files. So check for this also. I can't remember if Winamp has this or not. But the story rings a bell. Also, for windows, when an audio player realises it is no longer the default, it will ask you if you wish it to be the default next time you open that program. Also, installing new versions of audio players can change default. Audio players in windows seem to have a mighty battle on between each other to become the default player. Also keep in mind there's different types of audio files. eg: mp3pro which also has the mp3 extension, & of course m4a, etc.