HOW TO BLOCK USB drives (do 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. it required to restart the PC, USB is now blocked.

In case if you want to get the USB unblocked, just change the value again to 3.