Please back up all data before proceeding.
Step 1
Triple-click anywhere in the line below on this page to select it:
/Library/Preferences/SystemConfiguration/NetworkInterfaces.plist
Right-click or control-click the line and select
Services ▹ Reveal in Finder (or just Reveal)
from the contextual menu.* A folder should open with an item selected. Move the selected item to the Trash. You may be prompted for your administrator login password. Restart the computer and test.
If there's no change, repeat with this file:
/Library/Preferences/SystemConfiguration/com.apple.network.eapolclient.configuration.plist
*If you don't see the contextual menu item, copy the selected text to the Clipboard by pressing the key combination command-C. In the Finder, select
Go ▹ Go to Folder...
from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.
Log out, log back in, and test. If there's no improvement, continue.
Step 2
Reset your computer’s PRAM.
