In this Tutorial i show u, how to fix Stereo Mix problems, if your stereo mix is lost, u get no signal or its not work, so u can get it back and make it work...
Here the download link: http://adf.ly/1o6eMJ
(the version is not the same like in this video, but that version also should works well, because the other version i havnt found again, but i tryed that version out and it works also great :-)