Tsengal,
Try on another USB Port one you have not used the player on before if possible.
If that does not work disconnect your player, open device manager and right click on all usb root hubs and select uninstall then reboot your PC. When windows reboots it will reinstall the drivers the try again.
Also right click on My Computer and select Properties, Hardware Tab, Driver Signing and make sure it is set to
Ignore