Step1: In Windows 7  press Windows key+R and type as “regedit

Step 2: It will open the Registry Editor of  your Windows 7



Step 3: After opening Registry edit browse the following path in reght side bar of registry editor
The Path to go: “HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR”
Step4: Then right click the registry “Start” which is rectangled in red color in the below screenshot of registry editor
Step:5 Right Click “Start” and Click modify
  • To enable USB ports: change the value from “4″ to “3″
  • To disable USB ports: change the Value for “3″ to “4″

finaly restart your system.