The new Apple Airport Update 4.2 caused problems with some Mac (and possibly Windows) users. The Airport Update caused the AirPort Admin Utility to prompt users to upgrade their Airport Extreme or Airport Express firmware. Upgrading the firmware caused the wireless network to become unstable and users were disconnected from the network.

Read more about the Airport Update 4.2 Problems with Airport Extreme.

Step by Step Solution

1. Go to Apple Support.

2. Search for “airport firmware”.

3. Download and install the appropriate firmware. Choose the firmware version you had just prior to the faulty one.

Hint: To find the firmware version of your Airport Extreme or Airport Express, launch AirPort Admin Utility and look at the bottom of the first screen that appears. It should say something like “Apple Base Station V5.6″ (for the Airport Extreme).

Note: The older firmware you’re installing will overwrite the current firmware on the Airport. The problem should be resolved instantly. You can leave the AirPort Update 4.2 since that update wasn’t the one causing the problem, just the firmware upgrade.