This policy setting allows you to control whether anyone can interact with available networks UI on the logon screen. If you enable this policy setting, the PC's network connectivity state cannot be changed without signing into Windows. If you disable or don't configure this policy setting, any user can disconnect the PC from the network or can connect the PC to other available networks without signing into Windows.
Administrative Templates/
System/
Local Computer Policy -> Computer Configuration -> Administrative Templates -> System -> Logon
After changing group policy options, you need to update group policy. If you do not update group policy then settings will not effect. To update it just simply type below command and also sample image is shown.
gpupdate /force
In about command we used "/force" option, this will help up to update policy options forcefully.
