Update on grayed out wifi button in 4S:
I tried all the fixes and although some work unfortunately they turned out to be temporary. When I retry them none work for me. I did purchase the AppleCare plan so I arranged to send in the old phone in exchange for another 4S.
I chose to take the old phone to UPS store & when Apple received it, they overnight mailed the replacement to me.
Very short down time this method. Of course you have to go through setting up the replacement phone which I did with Apple tech walking me through it.
I highly recommend taking out Apple care insurance plan when ever you buy an Apple product, it is well worth it. No hassle dealing with them except for the time factor!