Block usb drive of computer.

To this what can be done is that the USB can be blocked and then stopping the use
of USB drives. Here is a simple registry trick to do so, try it with care.
1. Go to Start –> Run, type Regedit.
2. Go to HKEY_LOCAL_MACHINE\System\CurrentControlset\Servic es\USBStor
3. In the right pane, look for value Start and have value as 0000000(3)
4. Double click on that and change that value to 4.
You might be required to restart the computer, and then you are done with it, USB is
now blocked.
In case if you want to get the USB unblocked, just change the value again to 3