wi-fi no hardware installed

reinstall ios 7

While the laptop is starting up( I assue you have a laptop?) press command+R, pick english then go to the wifi bar at the top and check if you have wifi, if you do reistall ios 7. It worked for me,I hope it works for you.

OS X 10.7/ 10.8?

Reset PRAM. http://support.apple.com/kb/PH4405

Reset SMC. http://support.apple.com/kb/HT3964

Choose the method for:

"Resetting SMC on portables with a battery you should not remove on your own".

If this does not help, contact Apple.

Best.

OS X mountain lion. Not ios 7. Sorry