I have Audacity 2.4.2 in Windows 10 Pro in a new laptop. In prior use of Audacity I would open a track I want to record against, click on “track” then “add new” then “mono”, place the cursor at the start of the new mono track, hit “record” and record my new track while listening to the loaded track. With my new laptop and Audacity 2.4.2, the recording starts at the end of the loaded track, no matter what settings I try (including “record new track”). Any ideas? Thank you. Rob S.
There’s no need to “Add New”. Just click the “<<” (rewind) button to get the play cursor to the start of the track, then “Shift + Record button” (or “Shift + R”) to record to a new track.
Doesn’t work still. Still starts recording at end of imported track that I want to record to. Help! Thank you. Rob S.
Perhaps your “Shift” key doesn’t work 
Shift key works fine. It seems that cursor goes automatically to end of imported track whenever recording starts. Any ideas?
Did you “rewind” to the start before pressing “Shift + R”?
The “Home” key will rewind to start.
If your device panel is set to “2 (Stereo) Recording Channels”, Audacity will not record on a mono track. It will default to the end of the first stereo track.
JeffM. You are BRILLIANT! That solved the problem. Thank you! Thank you!!
Now to get the forehead dents out of my computer screen…
Glad I could help. I had the same problem 