How to fix wifi on iPhone 4S with iOS 7?

I can't turn my wifi on and I've tried resetting network settings and restoring iPhone but I still cannot turn it on. It's just greyed out I can't switch it over at all. What can I do to turn it on? Please help. & I can't update to latest iOS that fixes bugs because I can't update without being connected to wifi.:/ I'm annoyed. Please help!

Not to sure sorry, I have an android phone and it works great, I have never had any problems updating my OS

Just something to consider: P

Go onto your computer and go onto itunes

If you don't have itunes download it by searching itunes into google

Then back up your iphone by pressing back up

Then update your iphone, and it should update to ios 7.0.3.

Once done, check if it work, if not make a appointment to see someone at the apple shop