[Superkid11]

Once upon a time I used to be able to record any sound I played on my computer with the Line-in input using either WavePad or Audacity, no microphone needed. Before I switched from my old computer for some reason it stopped working, and I can't seem to do it on this one either. I do it mainly to record songs from Youtube Videos or anything else I can't directly extract it from. (My old computer had a tendency to change a random setting on occasion. It was weird.)
... or to record iTunes files.

Is there any particular thing I need to enable or download to be able to do this again?