This should work for WMP 12 on all Windows versions:
Close WMP and open Services
Find Portable Device Enumerator Service. In the registry, you'll find this at HKLM\SYSTEM\CurrentControlSet\Services\...
OneDrive takes large liberties with your folders when Backup
is specified (which is the default) for your folders of
Documents, Images and Downloads.
It will move these folders into its own folder and ...