What version of Windows do you have on your new computer, and what are you using for a sound card? Just the built in one?
I ask because, with Cool Edit Pro, 90% of the signal routing options are handled by Windows, not within Cool Edit itself. The first place I'd be looking is the Windows sound settings and make sure you have the right things selected on the Recording Tab and the Playback Tab--trouble is, exactly how to do this depends on the Windows version and the sound card.
The pessimist sees the glass as half empty. The optimist sees it as half full. The realist just drains the darn thing and gets a refill!