Users can use the extender with the different SSID and Passwords of the WiFi networks. But there isn’t any point in connecting the extender through 

If you are accessible to the WiFi networks of the extender, you can easily connect to the WiFi networks but you need the default SSID and Password for that. These steps are the same as the browser steps. If you are unable to find it then feed and you will easily find the login page soon this time. Just add the login details of the device. Even after a lot of time you get nothing then check the below steps.

To begin with, the setup just looks at the Lights on the Extender. If the light on the extender is blinking Red. Then, for sure you must be losing the connection very early. So first lookup for a proper power connection from the socket. Therefore, you need to search for the WPS button on the pre-existing router. But also make sure of having the same on the Extender. Just press first on the extender and then, press on the existing router. Now see if you have the blue Light properly blinking on both devices. If yes then your Linksys Range Extender Setup is complete here.