How to Disable USB ports in Windows 7/8

If you want to protect your data .So,you can disable USB port 
of your pc.there is given following steps to disable the USB port.
Step-1. Click on Start .
Step-2. Click on Run . If you cannot find
RUN, type it in the search box.
Step-3. Type "regedit" without quotes. Thiswill launch the Registry Editor.
Step-4. Navigate to 
HKEY_LOCAL_MACHINE\SYSTEM
\CurrentControlSet\Services
\usbstor.
Step-5. In the work area, double click on Start .
Step-6. In the Value Data box, enter 4.
Step-7. Click on OK.
Step-8. Close Registry Editor and refresh your desktop.
Step-9. To re-enable access to your USB
ports, enter 3 in the Value Data
box in step-6 .
Finish