I think that when you burn audio CDs with Nero, it deletes the temp Wavs as it goes. I guess that would be good in your case, but it can lead to errors. I use Acoustica for audio. It first creates Wavs for all tracks, then burn. I guess that would be bad in your case LOL
anyways, Windows is gonna start to cry for more room soon anyways, so I would do like lostman said.