I have been using audacity. Now I have lost all audio output EXCEPT for audacity. All other audio output on my computer is lost. Has anyone else had this problem
This can happen if you have connected a USB recording device to your computer.
If that is the problem, either disconnect the USB device from the computer, or change Windows to use the playback device you want to use. Please see this FAQ: Why have I lost sound after connecting a USB device on Windows?.
If you need more help please tell us what Audacity version you are using (all three numbers as described in the pink panel at the top of the page).