Why airplay stop when installed airport extreme

Question

After installing airport extreme, I cannot airplay from my iPhone 4S.

Answer 1

First check to make sure that the AirPort Extreme (AEBS) has been configured to allow the wireless to be extended.
Open AirPort Utility, select the AEBS and click Manual Setup
Click on the Wireless tab just below the row of icons in the setup window
Make sure there is a check mark next to "Allow this network to be extended"
Jot down the exact name of the wireless network and the type of security that the device is using
Click Update to save any changes
Perform a Factory Default Reset on the AirPort Express (AX) as follows:
Power down the AX for a few minutes
Hold in the reset button and keep holding it in another 10-12 seconds as you plug the AX back in to power
Release the reset button and allow 40-45 seconds for the AX to restart to a slow, blinking amber state
Connect an Ethernet cable from your computer to the AX
Open AirPort Utility and click Manual Setup
Click the Base Station tab below the icons to assign a name to the AX, device password and adjust Time Zone settings
Click on the Wireless tab and adjust your settings as follows:
Wireless Mode = Extend a wireless network
Wireless Network Name = Exact same name as your AEBS wireless network
Enter a check mark next to Allow wireless clients
Wireless Security = Exact same setting as the AEBS network
Wireless Password = Same password as the AEBS network
Confirm Password
Click Update to save settings.  Close AirPort Utility as soon as you see the message that the settings have been stored and wait 40-45 seconds for a green light.
Unplug the AX and move it to a location that is approximately 1/2 the distance from the AEBS to the area that needs more wireless coverage.
If you are using a PC, as your post indicates, the Windows Firewall will often block the connection between AirPort Utility and the AEBS or AX, so you may need to check the firewall settings for "blocked" connections, or you may need to "allow" a connection in the firewall application.