My Iphone Wi-fi not work. I've tried almost everything iPhone 4S

is the wifi toggle greyed out?

in some instances it could be a bug from the firmware installation. let me check some of the documents I have since I work as apples technical support

might be a problem with your actual wifi. Try resetting the router because in some cases that could be the problem, not the phone.

I can switch to on and off normally, i've tried to turn off and on  a zillion times... did not worked out...

I tried to put in Airplane Mode also... Did not help...

I just don't know what to do...

I've tried to connect through wi-fi at my house and other places as well... in fact i've tried in almost every place... it doesn't recognize any wi-fi network... it says: could not scan for wireless network...

I have the same problem.  I have a iPhone 4S running OS 5.1.1 on ATT.  I too have reset network settings to no avail.

It says it can't scan for wireless networks-it doesn't see any networks, not just my wifi network at home.  The 4G data works though.  The thing is, I haven't upgraded or downgraded firmware recently-it just stopped working. When I go on the wifi networks page in settings and it shows "WIFI" - ON, "Choose a Network" - spinning wheel of death, "Ask to Join Networks" - ON.  All the other computers, including an iPod touch can go on my home WIFI network without issue.

Its clearly not a problem with the airport extreme 2009 802.11N that I have running my network because my Macbook Pro, Powerbook G4, my iPod Touch 2nd Gen, and 2 apple TVs all connect just fine to the WIFI network.

The iPhone 4S also cannot connect to any other WIFI network, anywhere.  No networks even show up in its list.

Since it has to be a problem with the iPhone 4S, and a reset doesn't fix the issue, what else could I do to fix it?

Thanks for your help.

Also, bluetooth is not working.  I discovered on other forum support discussions that there may be an issue with the latest OS update.  Does anyone have a work around until Apple fixes the problem?