The solution posted by guest using
http://nwe00xmp3man.sourceforge.net/works great. Sony's stupid software won't install on my computer so my wife couldn't use her mp3 player. This enabled me to add music finally!
Here are more detailed instructions if needed:
1. Click on the link (best to right-click and open in new window or tab so you can still refer to this page):
http://nwe00xmp3man.sourceforge.net/
2. The page that opens provides some information about the program. Scroll to the bottom of the page and click on the link there.
3. Click download in the green box located in the upper right corner of the screen.
4. You should now see a list of files (JavaStage, nwe00xmp3man, Optionals). Click on "nwe00xmp3man".
5. You should now have a longer list of files (v0.17, v0.16, etc). You should also see the file "NW-E00X_MP3_File_Manager-0.17a.jar" or something similar if a newer version has been developed towards the top of the screen. If this file is not visible click on the highest "v0.xx" file (it is v0.17 as of the moment). The .jar file should now be available. Right click on the .jar file and "save as" on your desktop.
6. Click on the back button in your internet browser and then click on the "Optionals" file.
7. Right click on the OMGAUDIO.zip file and "save as" on your desktop.
From here the directions provided by guest are pretty clear. Format your mp3 player. Copy the .jar file and the unzipped OMGAUDIO folder to your player. To use double-click the .jar file in the player, browse to find the songs you want to add in your computer, use the buttons in the lower left corner of the program to add the songs, and then click on the save icon in the very bottom right corner of the program ("Write titles to player") and you're done.