Network Password

Recently, my computer has been asking me for a network password for Microsoft Networking, before I can enter Windows. I don't have a password or a username, which isn't so much of a problem because I always press "Cancel" and the screen goes away.

Unfortunately, having the screen come up every time I switch on may laptop is insanely annoying. I can't for the life of me figure out how to get rid of that screen and Microsoft's help page is so obscure I have more luck finding out how to turn my laptop into a blender than the answer to my problem.

How do I get rid of that screen, so it doesn't appear before Windows starts up?

Thank you in advance for your help.