A device that is disconnected from your Windows computer will not appear in device manager. So normally you cannot uninstall a disconnected device. This tip will make disconnected (or "hidden") device appear, and you'll be able to uninstall the device and its drivers.
1) Open a command prompt
2) type "set devmgr_show_nonpresent_devices=1"
3) In the same command prompt, start device manager: type "devmgmt.msc"
4) Click View - > Show hidden devices
Now hidden and disconnected devices will be shown but in opaque .