i have a recording problem – i place a track into audacity and press record, but it re-records the track. my vocals come out fine as well, but the track is re-recorded on top, so it is layered. i went through the preferences, but can’t find a solution to this!!! please help! thanks!

I presume that you are using Windows?

Open the Windows Mixer (or sound card control panel) by double clicking (or right clicking) on the loudspeaker icon near the clock (bottom right corner of screen).
Set the recording input to “Mic” or “Line-in” (depending on which you are using instead of “Stereo Mix”.