I specify that Windows 8.1, the content of the supplied CD-mini is not compatible and can not be installed. In loccurrence, there is frankly no need, so I do not withdraw points. I found inconsistencies between the user manual in French, compared to English. In general, I look always in English, as other languages are often translations from English, which can lead to errors. Again, I consider that ordinary Internet users now understand that one should never anything to install without having to visit the manufacturer's website and have read the forums and Amazon reviews. It is unrealistic to rely solely on the manual supplied, despite the best efforts of the manufacturers. Hear people complain about the summary manual etc. etc., it makes me a little smile. Search information with Google, it is not so difficult.
For an implementation without concern ... especially connect the plug (adapter) TP-Link as close as possible to a plug socket into which the existing network is already connected. In the case of a strip, both plugs should ideally be in the same strip. Press the button pairing plug already in the network, and do the same in a second time with this plug TP-Link. Wait 60 seconds, until the pairing is done. There is no need to have an Ethernet cable plugged into the plug TP-Link or connect the router / repeater / etc above.
Once the pairing is done, you can now reconnect your plug TP-Link elsewhere on the circuit. Last thing to know ... if you want to plug in another network, it is recommended once-pair the plug first. To do this, press the pairing button for 10 seconds at least. Then repeat the pairing as described above.