Q: wifi doesn't work with IOS 7

This can't be a hardware issue.  Too erratic and mine seems to have resolved itself today for no reason that I can figure out.  I tried the same trick I had tried a few times - shut down and restart the phone.  If my chipset had suddenly given out, it wouldn't randomly fix itself.  I've bought 2 Macs, 5 iPads, and 4 iPhones over the past couple of years and Apple has always been honest and helpful with my problems.  Disappointing that they aren't being honest here.

I tried this and it seemed to work.

1. Turn OFF find my phone
2. turn ON airplane mode
3. Do a master reset
   1. push top button and home button at the same time until the apple appears.
4. turn airplane mode OFF
5. my wifi immediatley came on
6. Whoot whoot

I think that Apple does this on purpose so we get frustrated enough to just upgrade.  Chi ching, money in the pocket for them.  They are making crazy money off of people always wanting the newest product and then there are those of us that just want what we have to work properly.  I'm still having issues but what can I do.  Nothing seems to be working and I've tried everything that has been suggested.  I'm waiting for a fix as my next tablet/phone will be a droid.

I cant decide if I want to restore my iphone through iturnes..

not to optimistic it will do anything but wipe my phone.

I would doubt it's intentional, but the iPhone was the first Apple product for me personally and seems likely to be my last.  Things happen and no updates are that smooth.  However, it's the attitude toward the customer that is offputting to me -- customer service was supposed to be one of the things that set Apple apart.  If they are just like everyone else, and their hardware seems so problematic according to their Geniuses, then there is no compelling reason for me to move toward Apple in the future.

Yes, iPhone 5 IOS 7, WIFI has been working since rebooting my router; (turnning off wait 10 sec. turn back on). I think about 3+ days now. Only issue was not connecting or loosing connection after the 6 to 7 upgrade. Every thing seems to be fine now.

The airplane mode off trick only worked for a while.  Sadness descended upon the house.

From the beginning I assumed this was a software problem as it occurred within hours after I upgraded to iOS 7.  However, I went to the Genius Bar (Tuesday evening, 9/24) and they issued me a new 4S free of charge (note: I purchased apple care w/my original phone).  Prior to leaving the store they made sure I was able to connect to wifi. I have not had a problem with wifi anywhere since I was issued a new phone. I guess at this point I feel it's a hardware / software combination bug.  Either way, if you are still covered under apple care I would recommend just going into the apple store and getting a new phone.

Hmm, this problem seems to have appeared in the beta period

  http://forums.macrumors.com/showthread.php?t=1597258

One of the messages in that thread talks about iCloud Keychain

"iCloud Keychain is the culprit for me.

I tried turning this function on again, went through all the steps and then got home and it had difficulty connecting and then I had to select it and the password was gone. I did not have this problem for all the days I had iCloud Keychain off. So, I turned iCloud Keychain off and, after getting on wifi w/password and such, back to normal.

This is the first iteration of iCloud Keychain, so I'm sure it'll improve in future beta releases, I'm staying away from it myself, will try again in beta 3 (next week!)"

I'm going to try that.  By the way, my iPhone4s seems fine, but my iPad (latest generation) is experiencing the problem.

I'm having the exact same problem! Updated my iPhone 4s OTA on sept. 18th, had working WiFi until saturday. After that the button greyed out, and there's not a single solution that works. Tried re-installing as existing phone, and also as new phone. Yesterday I called Apple tech support, and they tried all the same steps mentioned here in the discussion. The lady I spoke with first was very kind, and agreed with me that it couldn't be a hardware issue, but must have been in the ios update. Since she couldn't help me, I got to speak to her supervisor, who immediately told me it must be a hardware issue, and cannot be a software issue. After me telling him (strict but kind) that I didn't accept his answer, and definately didn't accept him telling me that I'd have to pay €200 for a "new" phone, he told me he'd escalate my problem to the enigneering department where they will decide if I become eligible for a new phone. It might just take around five working days before I receive the verdict... Terrible, terrible service by Apple...

The wifi on my 4s works fine except on my home wifi.  The Apple devices I have that do not have ios 7 work fine at home.  It's not a hardware issue.

Reboot your router.

Did that.  Not a permanent solution.

I've just updated to iOS 7.02 and it seems to work. let's wait to see what happens..

Does not look like ios 7.02 is available for 4s, or is it?