The only way that I know it can be done is if you have 2 sound cards in your computer, using one as your playback device, and from that soundcard, plug the line out into the line in on the other sound card, the second sound card is used as your recording device, where you would run a wave recorder.
that would record the audio only
or... if you wanted to record the audio & video.. that could be done if you had an S video or an rca video output on your video card, you could plug that into your video capture card... just make sure that you have lots of space on a hard drive