There is a program called iCare Data Recovery they will need to get by searching google, free version is available. There is a size limitation on how much you can download on the free version but if you post how much you like the program on a website or facebook they claim they will give you a code to unlock unlimited recovery.
Once installed on any windows machine just plug the mp3 player in and open the program.
When the program comes up click on lost partition recovery and click next.
You should now see where it list Sandisk Sport Player so highlight it and click next.
Will take roughly 15 minutes to discover all music on the device.
Click to download all files that have been discovered.
Viola, you have your music back.
The mp3 player, I connected with a JTAG yesterday and **bleep** they have it locked down (JTAGS connections are on the front of device under the cover). After I played around with the firmware I can say getting the player to work again is never going to happen, they have a hex file to program the device but it has a flag in the programming to specifically note when the device has come from an institution.
I told myself I never would pay to get something I already purchased back and I can say I didn’t have to!
A member of a forum suggested the below software utility (which is free) to rename all the MP3’s to their appropriate names. This is primarily useful if you plan on using Windows to play your music files vs using an android or an Ipod/Ipad/Iphone where this normally isn’t necessary as the files are labeled by the tag data still present on the mp3 file.
The musics names easily can be brought back to “normal” using freeware MP3Tag, a well-regarded tag editor, which has an option (among others) to change file names to what is in the title ID3 tag. Easy and fast, and can be done for a whole collection at a single time. http://www.mp3tag.de/en/index.html