Connecting a XP PC to a Airport Network via the LAN port of the Airport Extreme Base Station
You don't need a wireless adapter to connect an XP PC with a network card to an Airport network using an AEBS as you can plug it direct into the LAN port of the AEBS. You also don't need the Airport Admin Utility (AAU) in order to connect your XP machine to an Airport network.
You need to physically connect a network cable (ethernet CAT5 cable) between your XP PC and your AEBS. This means plug the cable into the LAN port of the AEBS and the ethernet port of your PC.
You are not doing anything on the PC at this point in terms of software or OS (it can (and probably should) be turned off). You are simply plugging in a cable between your PC and your AEBS.
Turn your PC on.
Open the Control Panel
Start -> Control Panel ->
Open Network Connections
You should see all your network connections similar to this screenshot.
If you can see any Network Bridges (unless you know you need them) delete them.
Select your Local Area Connection
Right Click the Local Area Connection which should be under the LAN connections and click Properties
This should bring up the following window.
On the General Tab you should see Connect using: the name of your ethernet adapter
Then a selection box entitled This connection uses the following items
Scroll down and select Internet Protocol (TCP/IP)
You now need to configure your TCP/IP settings?
For most users they should be Obtain an IP address automatically and Obtain DNS server address automatically .
It might also be worthwhile checking your internet settings
From the Control Panel select Internet Options
This will open a new window.
Click the Connections tab
Ensure that the Never dial a connection is checked.
Click LAN Settings
and check that all the settings are unchecked (especially the proxy