Connect the internet wire exactly to the tp-link Router device first port
White wire on the picture is the internet
Second black wire to the port number 3 is cable from router to the computer which has two Ethernet (network/LAN) cards called System server
On the operator screen (lower touchable display) go to windows settings-Network & Internet-WiFi-Change adapter options and here please find out which adapter is your “black” wire connected from the tp-link router to the System server/computer. You can find out by reconnecting the “black” wire and the adapter should show as not connected.
Click with the right mouse button on the adapter where the “black” wire is connected to, choose properties and double click on “Internet Protocol Version 4” option, choose here please both “Obtain IP/DNS server address automatically” and with OK buttons save it.