Stereomixer disappeared

I ve used audacity for about a year till tonight (:
I discovered that stereomixer disappeared. I reinstalled it several times, upgraded - nothing helped.
Could you help me to sort it out?

What exactly did you reinstall and upgrade? Reinstalling Audacity won’t help.

You need to go into the Windows Sound Control Panels to show and enable stereo mix, so that Audacity can see it.

See here if you are on Windows 2000 or XP: .

See here if you are on Windows Vista or later: .

If you need more help, PLEASE state your version of Windows (see the pink panel at the top of the page). Also give us the exact make and model number of the computer.