As others have said, it seems to me that you should try another WiFi connection.
You are trying to do TWO things at the same time here - it sounds like you don't even have a reliably-working WiFi connection, and you are trying to use it to register your Nook. Well, the first thing to do is to find a reliable connection. Then register your Nook.
Afterwards, you can worry about getting your own WiFi connection setup and working. It would probably be easier to use a laptop computer to diagnose your router problems, but I don't see how you could use an unregistered Nook for such a task.