Resetting AirPort Express:
How to perform a hard reset
If your AirPort Express stops responding, you may need to hard reset it. You can then restore settings from a saved profile or start all over with the AirPort Express Assistant (Windows), AirPort Setup Assistant 4.1 or later (Macintosh), or AirPort Admin Utility (either platform).
Important:
Hard resetting AirPort Express erases all settings other than saved profiles. The settings erased include Access Control and RADIUS settings. AirPort Express must be connected to power during this process.
The reset steps vary slightly depending on whether the version of firmware installed on AirPort Express is 6.1.1 or later (downloadable here), or earlier than 6.1.1.
For 6.1.1 or later
Push and hold the reset button.
Continue holding it until you see the status light (LED) start to flash rapidly, which should happen after about five seconds.
Release the button, and AirPort Express will reset.
