How do I prevent a phone's wifi from turning on by itself?

[Honkie McGee]

My wife does not want the WiFi turned on her Lumina 928. But when she check it a couple of days after turning it off, WiFi is back on. She has not updated her phone to 8.1.

 

[Guytronic]

Best way to keep it off is to delete the local connection in the list of available wifi in settings.
These phones always search for available Wi-Fi and connect if a router key is stored.

 

[NaytG]

There is a "reconnect automatically" setting in the wifi options you can uncheck. I think.

 

[andreizene]

When you turn off wireless from the settings application, a dropdown box will appear saying that the wifi will turn back on after 1 hour. Just change that to "Manually". You can still leave the connect automatically checkbox marked, since it shouldn't connect to any network if the Wifi is off.