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.Continue Reading
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 the Finder menu from your dock. You can also use any Finder menu that is already open on your desktop.
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.
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.
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.