Airport Express does't work after new router installed

The issue is that you now have two wireless networks operating. In order for the AirPort Utility to find the Express, you need to connect your Mac to the Express' wireless network first.

However, I don't have two wireless networks operating, just the new one. Perhaps my computer is still looking for the new network. If that's the case how do I connect to the "Express' wireless network," as you suggest?

Sorry, I was assuming that your new combination modem/router was wireless.

Ok, then in this case since you have two routers with NAT enabled in series, you should be experiencing a "Double NAT" situation. Even if you're not getting an error message, you will want to resolve this by reconfiguring the Express as a bridge.

Do you have another Mac running OS X Lion or Mountain Lion?

The new modem/router is both wireless and wired. It's plugged into the Ethernet wiring we ran through the house when we built it 10 years ago.

Ok. What is the make & model of this device. I assume that it is connected directly to either a DSL or cable connection for Internet access via that Ethernet connection ... correct?

And it acts as a wireless router.

Alright so this device IS providing a wireless network. What, then, is the networking goal for the AirPort Express? Do you want it to extend this device's wireless network or just for streaming iTunes/sharing a USB printer?

Thanks for the info. The basic steps to configure an AirPort Express for iTunes streaming is provided in the following Apple Support article. You can use it for reference. I would strongly recommend that you perform a "factory default" reset on the Express before carrying out any of the steps in the support article.

Don: I struggled with this problem after Comcast installed a powerful new wireless router combo in our house. All my AirPort Express units went non-functional, and I tried every "restore to factory settings" combo under the sun.

Ultimately, I believe Apple and Comcast devices aren't made to work together.

I solved the problem by connecting my AirPort Extreme to the Comcast Router via Ethernet, creating a new wireless network for music, and connecting my AirPort Expresses to the new network. It's an all-Apple solution. I wish I could suggest something more elegant.

I had the same issues with Comcast. First I plugged my TimeCapsule into my Comcast router and then I used Airport Express to extend my network into my family room so I could stream video and work my APPLE TV in my bedroom. The guy who installed my TV installed Apple TV using an Ethernet cable and then he hooked the Apple TV to HDMI.

I meant the technician installed my family room Apple TV via Ethernet he dragged through my basement and then HDMI hookup to my TV. The bedroom TV works on wifi through my Apple wireless Network

I have the same situation. No more music as the Express no longer connects to the new Xfinity wifi.

I was told by both the Xfinity people and a Mac Store person that the Xfinity modem/router won't "talk" to the Apple Express.

I had a similar problem. When Verizon installed a new router in our house, we created a new wifi network. The Express was still talking to the old wifi network and blinking Amber. I didn't see any way in the Airport Utility to reconfigure the Express to see the new network until I connected the Express to the new router via an Ethernet cable. Once I did that, I found the page to connect to the new network and to add the network password.

Then I moved the Express back to the living room and plugged in the connection to the stereo amplifier. Voila. I was back in business, streaming music from my iPhone and iPad.

I have the same problem as ersol55 and it looks like their solution might work for me. My Airport Express is connected to the Xfinity router via Ethernet, What I need to know is what page to go to connect to the new network and how to find the password.