Airport Express can only extend network, not create new one. Why?

When connected directly to another non-AirPort router via Ethernet the only way to "extend" that other router's wireless network is via a roaming network configuration. Since the ISP's router has changed, I would start all over again with establishing this type of network.

Do you want this wireless network to also have Internet access? If so, the AirPort Express MUST be connected back to the other router via an Ethernet connection. If not, then you can just use the Express in its default configuration which broadcasts an unsecured wireless network with a network name of something like: Apple Network NNNNNN ... but it will not have Internet access.

What have I done wrong with the configuration?

Open Macintosh HD > Applications > Utilities > AirPort Utility

Click on the AirPort Express icon

Look for the Status of the connection to see if there are any amber dots that you see

Report back with any errors that are listed next to an amber dot

Example below:

Thanks for posting the screenshots. I cannot duplicate this when I try to create a new network, but I am using an Apple router, so I cannot test with another brand of router.

Please try to reconfigure the Express to "extend a wireless network" If you can do that, we may be able to go back in using AirPort Utility and change the name of the wireless network. Then you will have your own network.

Post back when you have the Express set up to "extend".

Edited post above.

I bought an Airport Express, connected it to the shared router with an ethernet cable and set up a wireless network of my own in my room.

Sorry, but the screenshots that you posted indicate that the Express is connecting using wireless only.....not Ethernet. I understood from your information just above that you have an Ethernet connection established between the router and the AirPort Express.

If Ethernet was active, there would be a solid line between the connection and Express.....not a dotted line.

Please clarify

You cannot have a wireless connection while an Ethernet cable is connected at the same time. This creates "looping" Things will never work this way.

When I said "extend", I meant the original setup of the device. Reset the Express back to factory defaults, connect the Express using Ethernet and accept the option to "extend" the network.

If this works, you will be connected using Ethernet and you will have the same wireless network name as the main network.

Then, you can go back in using AirPort Utility and manually edit the wireless network name to anything that you want. Then you have your own network.

I just tried this with my AirPort Express connecting to a Netgear router at my neighbor's.

Start from a Factory Default Reset

Connect using Ethernet

Start AirPort Setup and let it analyze the network and announce that the Express will be setup to "extend"

Follow the steps

Now the Express will be broadcasting a signal with the same wireless network name.

Now it is easy to to change the name of the wireless network and password using AirPort Utility...so you have a new network with a new password.

It works fine. I am using it right now to type this.

None. You need the option to "extend" the network. Sorry, but I cannot help if this option does not appear. The same option appeared when I connected the Express to my neighbor's Netgear router.

If you have an Apple Store or servicer near you, you might want to let them check the Express.

Another option is to use a different version of AirPort Utility. Post back if you are interested.