The WiFi setting on my iphone 4 is turned off (It says "No WiFi") and I can't change it. The whole setting has that faded grey color. So of course I can't connect to my home router and must use the 3G all the time. How do I turn it back pn?
Take a look at this Apple support page:
Go through the suggestions starting at the top until you have corrected the problem.
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