Disable / Enable USB ports on Windows XP, 7 or Vista PC via Registry

With this trick, you can disable access to your USB(Universal Serial Bus) ports in your Windows based PC to prevent people from taking out data from your personal computer without permission or spreading viruses through the use of USB(pen and flash) drives.

To use this trick to disable USB ports, follow the steps given below:-

1. Click on Start.
2. Click on Run.
3. Type "regedit" without quotes. This will launch the Registry Editor.
4. Navigate to  HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\usbstor.
5. In the work area, double click on Start.
6. In the Value Data box, enter 4.
7. Click on OK.
8. Close Registry Editor and refresh your desktop.
9. To re-enable access to your USB ports, enter 3 in the Value Data box in Step 6.