1. Goto run 2. Type 'regedit' without quotes 3. Click on HKEY_LOCAL_MACHINE 4. goto SYSTEM 5. Click on CurrentControlSet 6. Click on services 7. Goto USBSTOR 8. Double click on 'Start' where value is 3 9. Now change the value data with 4 10. Now press ok and refresh your desktop your USB port is disabled, to enable the usb port replace the value 4 with 3