I'm not a Napster subscriber, but I'm a YMU (soon to be Rhapsody) member. I have bought tracks from various online stores. I'll try to help.
I sometimes use the tool in WMP11 to sort my library by online store. If you purchased tracks from Napster, this may not help because your sub tracks and purchased tracks will be lumped together.
Secondly, can you still long in to Napster even without paying? Most of the sub services keep your membership info and library intact, you just can't play the sub tunes. Then while logged in, you could sort by "file type" and delete the sub tracks from within Napster?
Finally, I have found that purchased tracks and sub tracks have different numbering systems in their file names. For instance, my sub tracks from Yahoo have a "-0" after the track number, while purchased tracks have a "-2". So if you add the file name column to your library view, look at Napster tracks from step one, then you could go through the tracks that way.
Sorry if this wasn't helpful, I can only picture how I would do it based on my experience with YMU.
I stopped subscribing to Napster music service, now I want an easy way to remove all that music that is taking up space and annoying the Windows player with asking me to log back to napster.
I use Windows Media Player 11. I was able to sort music as DRM free or not. But, unfortunately it does not discriminated between DRM of subscription and bought tracks.
Anybody have any suggestion, or must I delete track by track.