Tutorial Enable USB Port through Regedit in Windows if it is blocked

1. Click Start, and then click Run.
2. In the Open box, type regedit, and then click OK.
3. Locate, and then click the following registry key:

HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor

4. In the right pane, double-click "Start".
5. In the Value data box, type "3" (without quotes), click Hexadecimal (if it is not already selected), and then click OK. Note :- if 3 is entered it will open the port and if 4 is entered it will close the port.
6. Quit Registry Editor.