Unfortunately, Apple tells us that the "extend a wireless network" feature will only work when you have the Express extending another Apple router.
In other words, to "extend" it takes a minimum of two Apple routers.
Your Express has "joined" the network. You can use it for AirTunes or connect a remote printer, but it will not "extend" the signal from the Motorola modem/router and provide more wireless signal coverage.
You would need to connect the Express to the Motorola modem/router using a wired Ethernet connection if you want it to provide more wireless coverage. In this case, the Express would be configured to "create" a wireless network using the same wireless network name, same security settings and same password as the Motorola network. The Express must also be configured to operate in Bridge Mode in this type of setup.
Thanks Bob for the quick response and help. I now understand how I need to connect the Express with the Motorola.
To confirm, if I want to extend the range of the network, I need to purchase another Express and set it up to "extend a wireless network" in order to get the range of the network expanded. Is this correct?
All the best,
One Express must be connected to your Motorola modem/router with an Ethernet cable. That Express must be configured to "Create a wireless network".
A second Express needs to be located approximately half to two-thirds the distance from the main Express and the general area that needs more wireless coverage. That second Express will pick up the signal from the main Express using wireless only and re-broadcast the signal, providing more wireless signal coverage in the general area where it is located.
You will not be using the wireless signal provided by the Motorola wireless modem/router at all, so unless you really need a second wireless network, you should turn off the wireless function of the Motorola modem/router.
Bob I wished I would have known about the not being able to extend the range between the non apple to apple (as I am using a Motorola wireless). Not knowing too much about the hardware and I hope I am not putting you on the spot but would I get more performance with a TimeCapsule (airport extreme) with my wifi turned off on my SBG6580? I had bought a Airport express for the visions of extending the range of my signal to the far end of my house. Being new to Apple I just assumed my problem was a subtle problem I was missing.