I just recently brought the 8gb sansa fuze. The other day, I downloaded music through windows player and had no problems. Yesterday, I connect it to the computer, and it says that it does not recognize usb device. What’s up with that?
Try to restart your computer and plug back in.
try uninstalling WMP11 (if you have it) and reinstalling it. it should refresh the drivers.
I solved this by simply changing the Fuze preference from AutoDetect to MSC in System>System Settings>USB Mode.
MSC will enable you to drag and drop your files to the Fuze, while MTP is used by Microsoft WMP. Since I don’t use WMP, it’s no big deal for me.