I have an apple imac set up with an airport express device, I am trying to set up a second airport express device and the system isn't recognizing it

This was helpful. What I had to do was to take the airport express device and use a LAN cable and hook it directly to my computer. I then reset up the system, unhooked it and placed it remotely where I needed it in the house (stereo downstairs) and completed the set up and all is fine. Thanks.