won't record when attempting to tranfer tape to computer

I’m using Windows XP and Audicity 2.1. I’m just learning to transfer cassette tapes to my computer. I was successful in transferring 3 songs, but now when I try, it won’t record. I’ve double-checked my cords, the tape plays when not connected to the computer, but no sound is recorded when I push—‘record’ and ‘play’ on the cassette player. Help!

How is your tape player connected to the computer?

I presume that you are aware of the warnings about using an obsolete operating system?