how do I get the network connection window to stop popping up?
It is likely that you just need to delete one of the connections in Network Preferences.

Go to System Preferences > Network

You will likely have a list of connections on the left, Ethernet, Wi-Fi, etc. One of them is likely the connection above.

Click on each of them, in turn till you find the one that corresponds to the connection in your question. Click on the "-" at the bottom left to delete the selected connection.

That should do it. If not then we will need the screen captures "TheBro21" asked for.