amnman,
I doubt you need any software for a USB pendrive MP3 Player. Just connect the player to your PC and use it as a you would a USB Pendrive by copying your MP3 files to it with Explorer.
The two tools that would apply to your player are the firmware upgrade tool but upgrading the firmware is not advised as it can very easily kill your player. Secondly s1fwx which is used to create a backup of your players firmware. This is a good idea because if you do ever have problems with the player the firmware backup can be very handy.
You can download s1fwx here:
http://www.mympxplayer.org/s1fwx-31-df417.html
And should you ever need it the upgrade tool:
http://uploaded.to/?id=e18496
You will find Guides to using both programs in the Knowledge Base Here:
http://www.mympxplayer.org/imageknow...base-vf13.html