I'm helping my girlfriend's mom with an issue. She has her keyboard hooked up to the Line In. Audacity is recording off of the Line In and playing through the Line Out to the speakers. Everything works fine. There's no feedback or real delay in hearing the sound.

The problem is when she goes to record another track over top of that. She wants to hear the first one so she knows when/what to play, but it's rerecording the first track onto the second. This is an issue, obviously. How do I fix that?

Edit: Nevermind, fixed it. I just had to mute all the other "recording" volumes in Windows' sound options.