Sansa m250 Not Showing Music Directory

The unit works on one PC (laptop at home) but not the other (Desktop at work). Both machines are running XP SP3.

The one it works on shows it (Windows Explorer) as a portable device with a name  TCNAND0. I click the name and it opens to 3 directories and I can see the music files.

The one it doesn’t work on shows it as either a USB with no Music directory, or I can set it as a Windows MTP device in which case I can’t open to extract the music files.  Windows Media player see the files and I can play them but it doesn’t give me an option to extract them.

Any help appreciated.