I purchased an AV600 Powerline WiFi Kit. It says it is plug and play, so I should be able to plug one into my router and the other where I want to extend the WiFi and I should be able to connect. I have tested this on my iPad. I went to WiFi settings and there was an option to join the network "TP-Link xxxx". I did this and had three bars of signal but it would not open any web pages. It started to load, then froze, then said the server had stopped responding. I also tried to unify the WiFi networks but after pressing the WPS button on the router, then the pair button on the WiFi extender, the WiFi LED did not start blinking as it said it should.

What do I need to do to get this to work?