AirPort Extreme Serving via Ethernet?

[Kuru Kuru]

Here's a network setup scenario I'm trying to enact that I need a little guidance on:

I have two pieces of AirPort routing hardware, an Express and an Extreme. I am using the Express as the router for my network since it was the only one that my friend's Windows laptop could connect to the internet through. So, the Extreme is just sitting around at the moment.

My plan is this:
-Connect the Extreme within the Express's network
-Connect an ethernet hub to the LAN port on the Extreme
-Connect my two non-wireless desktop computers to the hub
...And have the connection (network and internet) served to them via the ethernet through the Extreme.

The final factor:
One desktop is running Mac OS X 10.4, and the other is running Windows XP SP2.

This wasn't described in the manual that I could find. If someone can point me to an obvious thing I'm missing that would be just as appreciated as anything else, hehe.
Okay, have at it!

 

[techound1]

Hmmm...

Here's what I'm doing with 3 Macs on OS X and 2 PCs on XPpro SP2, all wireless:

The Extreme is my "hub" (no problems with the PCs connection there), I have two expresses as print servers and one as an itunes server. I connect the cable modem to the extreme and everything else is wireless.

PCs have been a historic PIA for mixing with Apple wirelessly. Were I you, I would shut everything off (including the PCs), and rebuild the network starting with the extreme and the PCs. With the extreme as the only thing on, the PCs *should* be able to see it and connect.