Resetting Wi-Fi preferences

If your wireless connection is not working these are instructions to reset the Wi-Fi settings

Objective

Trash Existing Wi-Fi Preferences in OS X to Start Fresh.

Mac, Apple, OS X, Wi-Fi, wireless

Create a new folder on your Desktop called ‘Wi-Fi prefs backup’ or something obvious.
Turn off Wi-Fi from the menu item in the upper right corner of the OS X.
Go to the Finder (the smiley face icon in the Dock), and press Command+Shift+G to bring up the Go To Folder command, choose the following path exactly: /Library/Preferences/SystemConfiguration/
Press Return to go to that folder, then locate and select the following files:
- com.apple.airport.preferences.plist 
- com.apple.network.identification.plist
- com.apple.wifi.message-tracer.plist
- NetworkInterfaces.plist
- preferences.plist
Move all of these files into the folder you created in Step 1 on the desktop (you can also delete them if you’re confident and have made a backup).
Reboot the Mac.
Turn on Wi-Fi from the wireless network menu again in the upper right corner of OS X.

If your Wi-Fi works now, great, but for most users, you’re not quite finished yet! Now you need to create a new custom network location.