I haven’t been able to upgrade since 6. When I did that, it eliminated my ability to use the wi-fi setting. It’ greyed out and unusable. If anyone knows how to restore that function I’m all ears. May not matter, though. Looking to upgrade my phone to 5s or better. But in the meantime, any help is welcome.
I haven’t heard of that directly myself, but if you wanted to do a method of “last resort” - I would resort to doing a full backup on iTunes - or if you have set things up in the cloud, do Apple’s backup in the cloud. You might read up on the differences between the two to make sure you understand, though.
Then I would do a RESET back to original factory condition. After the reset, the start it up just like you got it brand new, when no one had ever used it before.
NOW ... this next step may not be necessary, but I would do it - just to make sure. I would not do a restore at that time (the machine will ask you). I would start it up as a new device and then see if your WiFi is working under those conditions. Hopefully it is, and then you can go on.
If it’s not - from that factory-fresh restart - then I would take it to the Genius Bar at the Apple Store and get them to do some hardware/software diagnosis.
In the event it does work - then I would go back and do the factory restore once more - and this time, when asked, I would restore from my backup - to bring back all your stuff.
HOWEVER ... you can also go to the Apple Forum and get other users’ advice and help, too. It’s at ...
https://discussions.apple.com/index.jspa
Sometimes it’s best just to go to the Genius Bar. It’s free and almost always the answer is simple and solved immediately.