I found this device almost impossible to set up. I bought 2 and returned them as being defective until I finally managed to set one up. The instructions supplied are totally inadequate to explaIn what to do when the device refuses to initiate and the dreaded amber light flashes. I have an AirPort Extreme base station and another, earlier generation, Express (which set up no problem incidentally!), this Express was to be for streaming music / printer duties.
When the amber flashed I tried everything, disconnecting the firewall, re-setting - nothing worked, the device wasn't detected by Airport Utility. Eventually I Googled the problem and found a solution: connect the misbehaving device directly into my PC via the ethernet port and conduct the set-up via Airport Utility that way. Instant success! Why doesn't the documentation supply that advice?
Now that it's set up, the Express is working fine as a music streamer but it has caused a lot of needless anxiety. Another thing is that the manual refers you to apple.com for support which takes you to the US site which is of no use whatsoever to UK punters.
I hope my experience is of help to future buyers who may experience similar problems.
Having set up 100's of Airport networks I would have thought ti would take a few minutes.
4 complete resets later I have finally got it playing nicely
However the Airprint feature doesn't work for me, The blurb says just plug the USB in and away you go.. Then if you read the very faint text and the bottom of the page (light grey on white) only compatible printers work!
Disappointed it wasn't clearer on the website