Hey  @Sohker,

Since your RE is expecting the Wi-Fi of your previous router, you will need to reconfigure the range extender for your new Wi-Fi. Since you have had difficulties, I would recommend resetting the Range Extender to factory defaults so that it can be ensured that there are no leftover settings. After being reset, the device should broadcast a setup Wi-Fi setup - which should be easily identifiable from your main and nearby networks.

you can then connect to this network and configure the device through the Tether App or web browser if using a PC.

  @MrRemy920,

I would recommend creating a new thread and providing a bit more information about what you have done to try and get the device to connect and where, in the process you experience problems. Range Extenders will work with basically any Wi-Fi network, so you simply try one of the other setup methods such as via the WebUI, Tether App, or even via WPS