2. The situation to block the USB will fall in either of the categories :
(a) USB storage device is not installed in system
(b) USB storage device is already installed in system
CASE -1 : USB STORAGE DEVICE IS NOT INSTALLED IN SYSTEM
- Type %windir%\inf in Explorer address bar or RUN dialog box and press Enter. It'll open "inf" folder.
- Now look for following 2 files:
usbstor.inf
usbstor.pnf
3. Now to change their user permissions setting Right-click on each file and select "Properties". Goto "Security" tab and select the desired user or group in "Group or user names" list which you want to restrict from using USB drives. Now in "Permissions for Users" list, click on "Deny" checkbox next to "Full control" option and then click on OK.
4. That's it. Now users will not be able to install any USB storage device in system.
CASE 2 : IF THE USB STORAGE DEVICE IS ALREADY INSTALLED IN SYSTEM
5. Type regedit in the run taskbar and reach at :
HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\UsbStor
6. In right-side pane, change value of "Start" to 4
7. Now whenever a user will attach a USB storage device which is already installed in system, Windows will not detect it and it'll not be shown in My Computer.
NOTE: If you want to revert it back to default, then change the value of "Start" to 3.