Turn off the Wi-Fi from the top panel, then delete preference files from the System Configuration folder to troubleshoot a wireless connection on a Mac. You need a Mac desktop or laptop computer and a wireless network to get started.
- Turn off the Wi-Fi
Log into your user account, and click the Wi-Fi icon on your top panel. Select Turn Wi-Fi Off to disconnect your computer from your wireless network.
- Open a Finder menu
Open the Finder menu from your dock. You can also use any Finder menu that is already open on your desktop.
- Navigate to the System Configuration folder
From the Finder window, select Command, Shift and G to reveal the Go to Folder text field. Type "/Library/Preferences/SystemConfiguration/" without quotes, making sure to start the text with a backslash and not a tilde (~) mark.
- Delete the preference files
Look for the files labeled "com.apple.airport.preferences.plist," "com.apple.network.identification.plist," "NetworkInterfaces.plist" and "preferences.plist" in the folder. Make a backup of these files, and place them in a new folder labeled Backup. Delete the original files.
- Reboot the Mac
Empty the trash from the bin on the dock. Next, restart the Mac. Turn on the Wi-Fi connection, and reconnect to your wireless network.