Here’s what worked for me:
Open Finder.
From the Menu at the top, choose ‘Go’ -> ‘Computer’.
Open your hard drive (probably called ‘Macintosh HD’).
Open the ‘Library’ folder.
Open the ‘Preferences’ folder.
Locate the ‘SystemConfiguration’ folder (likely at the bottom).
Drag this folder to your desktop (as far as I can tell, this is to back it up incase something goes wrong)
Once the copy is complete, drag the original to the trash.
In Finder, open Applications (If you don’t have it on the sideback, use ‘Go’ -> ‘Applications’).
Open the ‘Utilities’ folder.
Open ‘Keychain Access’.
Select ‘login’ from the list of Keychains.
In the list to the right, locate an object with the name of your wireless network.
Select it and press ‘delete’ on your keyboard.
Select ‘System’ from the list of Keychains.
Repeat steps 13 and 14 above.
Restart your MacBook.
Once your computer has restarted, connect to your wireless network.
Robert Ogden on 07 Jan 13"Click on the link to download the package and select 'Run' or 'Open'. You will be asked to accept the end-user license agreement (EULA) before you gain access to the package contents. The package contains 4 different files. Pick a location where you would like to place the 4 files above by clicking on 'Browse'. Once you have specified the location to place the extracted files, click 'Ok'. Launch an elevated Command Prompt by navigating to Start -> All Programs -> Accessories -> and then right click on "Command Prompt" and select "Run as Administrator". Type "CD" followed by the path to where you have extracted the 4 files in step 2 above. In the Command Prompt, type "ie9_blocker.cmd /B" and hit Enter to set the blocker on the machine. You will see confirmation in the Command Prompt: "Blocking deployment of Internet Explorer 9 on the local machine. The operation completed successfully." You can now close the Command Prompt window. "
