HKEY_LOCAL_MACHINE > Software > Policies > Microsoft > Windows > WindowsUpdate
In the left pane of the Registry Editor, click on AU under WindowsUpdate to have its contents displayed in the right pane.
In the right pane of the Registry Editor, locate and double click on the registry value titled UseWUServer to modify it.
Replace whatever is in the registry value’s Value data field with 0 and click on OK.
Close the Registry Editor.
Restart Windows Update service