There's only so much the Editing Tools can do. If there are pops, hisses, etc, then yes you can clean it using the Nero WAV Editor.
But if the source captuered is so mangled that you can not here the words or the background music, then this is beyond what Nero WAV editors tools can resolve.
You would need to find out why this is occuring to begin with. I assume that when you are capturing, and listening to the song being captured over your speakers, that the input is not coming in as 'Gibberish'?
If not, then we need to look as the drivers for your sound card.
I did a quick test before responding to this Email, using a Creative Labs Sound card on Window XP, I find no trouble with Nero SoundTrax capturing audio. It split the tracks, without problems, and playback is clean all the way through the album.