Disable USB in Windows systems

If a USB storage device is already installed on the computer, set the Start value in the following registry key to 4:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStorWhen you do this, the USB storage device does not work when the user connects the device to the computer. To set the Start value, follow these steps:
Click Start, and then click Run.
In the Open box, type regedit, and then click OK.
Locate and then click the following registry key:
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
In the details pane, double-click Start.
In the Value data box, type 4, click Hexadecimal (if it is not already selected), and then click OK.
Exit Registry Editor.