Hello,
I've seen this problem posted in several forums but there never seems to be a conclusive answer or one that fits my case.
I want to be able to record my screen (including audio) in addition to my voice in an external microphone. This means setting up Stereo Mix and (in my case) Jack Mic as active recording devices. But whenever I set one, the other changes to being "Currently unavailable". I can't even do the listen-to-this-device trick with the mic because it's unavailable.
I can't think of a work-around here because I need to be communicating with someone else while recording.
I'm running Windows 8 on a Dell Inspiron 7720.