no recording

hello everybody,
i upgraded to w7 from xp and since, audacity won’t work.
the stereo mixer is correctly set and when i want to record with audacity i have a flat line and nothing helps.
when i switch to microphone, it records normally.
i have the adequate realtek driver and the sound works fine

Stereo Mix may require updating your sound device drivers, if it works at all. Try recording with Windows WASAPI (loopback) instead: