Mp3 Files missing

When I copied music and audiobooks from my harddisc on my Fuze I used the explorer and this worked good until it change from a removable media to an internal memory. Now I cannot find some music files when I use the explorer (e.g. I cannot find a audiobook but the other audiobooks I have copied are still there). I can hear the “lost” files with my fuze.

Can someone tell me how I can find this files??

Go to Settings and change the USB mode to find your missing files.

The Fuze has two USB modes, MSC (works like a hard drive) and MTP (transfers through Windows Media Player). The Fuze sees all the files on the unit but your computer can only see ONE MODE AT A TIME: either MSC or MTP. To keep from going crazy, choose a mode and stick with it. 

Now it works. Thanks for the quick help.