To administer the original AirPort Base Station (Graphite) or second-generation AirPort Base Station (Dual Ethernet) from a Mac OS X 10.4 "Tiger" computer, you must use AirPort Admin Utility.
The version of AirPort Setup Assistant included with Tiger can't be used with the older base stations, and the older version of the assistant cannot be installed on Tiger.
The one exception is if you upgraded your computer from Mac OS X 10.3 with AirPort 4.1 software to 10.4. Under this circumstance, the "AirPort Setup Assistant for Graphite or Snow" may be carried over into 10.4. Though it may remain on your system after an upgrade, it will not actually work. It is left so that you may use it in the event that you "dual boot" your computer. In certain situations, this may also be called "AirPort Setup Assistant for Graphite and Snow."
Note: "Snow" is an alternate name for the second-generation AirPort Base Station (Dual Ethernet).