I have had the same problem since updating my iPhone 4S to iOS7. Apple thought at first it was a problem with my phone, as all the other apple products were working fine, whether they were updated or not. I did all of the steps above. Even set up my iPhone as a new one instead of restoring the back ups. Nothing. I could however join the Cloud hike outside. So Apple then ugh eyed it could be a router problem. So again I reset all network settings on my phone, reset my Belkin router to factory settings and then restored them again. Changed SSID settings. Nothing. Reverted to the original backed up settings. Nothing. Only with the difference that now the two iPods 3 running iOS4 and my old iPhone 3GS work as always. My two iPads 2 running iOS6, my iPhone 4S running iOS7, my husband's iPad 2 and 3 also running iOS7 have stopped working. The good thing is that now it involves him as well I am not the only one bearing the burden. But between the two of us we now have two useless iPads and two iPhones and two work iPads running low on 3G data as the wifi just won't work. We get the same message again: unable to join the network.
Saying that I am furious isn't an understatement. I have been working at this since the 23rd September and I am not a happy bunny. Why would my Belkin work with iOS4 and iOS5 and not with 6 and 7???? What on earth changed overnight as I updated my 4s to iOS and what changed with the others in the meantime? Seriously, I am so close to throwing all the apple stuff out and, dare I say it, look elsewhere. Can't take this anymore!
What else is left to try? Would buying a new router help? What brand would be best?
Any help greatly appreciated!