How could I record any sound that the computer is playing? Was it a movie, game, etc...

The library FMOD has some function to record sounds from the microphone, but I don't remember if you can specify the source (i.e. line in) or not. You may want to look at it...

I think that he's talking about recording what the computer is putting out... in that case you might want to look into this post which describes how to record from your speaker out in winXP.

Open up the windows volume control dialog, then hit options>properties, then select 'recording' and hit ok. Select Stereo Mix instead of Line In or Mic, and you're good to go.

Sorry, above post was me ^

If you have a Creative sound card, double click the Creative Volume Control then change the Rec button to "What U Hear"

I appreciate your answers.