We already responded to your other post, and it is confusing when you post again, rather than use the same original thread. We don't really know which thread to respond to at this point.
1) I assume that you have connected....and will leave connected at all times.....an Ethernet cable from one of the LAN <--> Ethernet ports on the Frontier modem/router to the WAN "O" port on the AirPort Extreme, correct?
2) And, I assume that you have located the AirPort Extreme in the area where it is needed......likely several rooms away from the Frontier modem/router, correct?
Note......Both of these conditions must be met if you want the AirPort Extreme to extend the signal from the Frontier modem/router wireless. Otherwise, the AirPort Extreme will not work correctly.
Open up AirPort Utility, click on the picture of the AirPort Extreme and click Edit in the smaller window that appears.
Click the Wireless tab at the top of the next window that appears.
Network Mode = Create a wireless network
Wireless Network Name = Same name as the Frontier wireless network
Wireless Security = WPA2 Personal (This assumes that the Frontier modem/router is using standard industry settings)
Wireless Password = Same password as the Frontier wireless
Verify Password = Confirm the password again
Click the Internet tab at the top of the window
Connect Using = DHCP
Click the Network tab at the top of the window
Router Mode = Off (Bridge Mode)
Click Update at the lower right of the window and give the AirPort Extreme a full minute to restart. You should have a green light on the AirPort at this time
Very Important......
Power off the AriPort Extreme by pulling the power cord from the back of the device
Power off the Frontier modem/router either by turning it off, or pulling the power cord
Wait a minute or two
Power up the Frontier modem/router and let it run a full minute
Power up the AirPort Extreme and let it run a full minute
Report on your results
