Wifi not configured

Try the following on your Mac in order, until (hopefully) resolved:

1. Create a New User Account
   • System Preferences > Accounts
   • Click "+" to add a new account.
   • Log off, and then, log back on with the new user account.
   • Try connecting to a Wi-Fi network with your Mac's AirPort.
   • If this resolves the problem, there may be something amiss with your current profile and will require further troubleshooting.
   • If this does not resolve the problem, go ahead and log back into your normal account and go on to the next three steps.
2. Delete AirPort Keychain Entries
   • Launch the "Keychain Access" application located in Applications/Utilities.
   • In the windows on the left side: Select login for Keychains and "Passwords" for Category.
   • Click on the "Kind" filter at the top, and look for any "AirPort network password" entries...and delete them.
   • Close Keychain Access.
3. Delete Preferred Network(s)
   • System Preferences > Network > Wi-Fi > Advanced > Wi-Fi tab
   • Delete all entries under "Preferred Networks."
   • Click on OK.
4. Add Preferred Network(s)
   • System Preferences > Network > Wi-Fi > Advanced > Wi-Fi tab
   • Add the preferred network(s) using the "+" button.
   • Click on OK.
   • Restart or log out, and then, back in.
     • If it works, then you are done.
     • If not, go on to the next step.
5. Move System Configuration Files

In Finder, go to /Macintosh HD/Library/Preferences/

Possibly. I suggest trying to add the Wi-Fi connector again.

• Go to System Preferences > Network
• Unlock if required.
• Click on the plus "+" sign to add a network connector.
• For Interface, choose: Wi-Fi
• For Service Name, choose: Wi-Fi
• Click on Create.

You should now have the Wi-Fi connector back.