"Set Network Location" box appeared for no reason

I have a Windows 7 computer which I've been using for eight weeks. This morning when I booted, it displayed the "Set Network Location" dialog box for no reason. I haven't changed any of my network settings. I selected Home and everything seemed to be okay. I rebooted and no, that box did not appear again.

Do you have any idea why that box popped up?? I did nothing the previous time that would cause it. It's always been set to Home. I have an older DSL modem and no wifi, and just one desktop computer and Norton.

(This is the same box that appears if I go to Control Panel > Networking and click on "Home.")

The same thing just happened to me! It's been two years since it last happened.
I know that's a long time but it should never happen.

When I booted today, I got a dialog box about networking:

http://blogs.msdn.com/blogfiles/e7/W...ge_thumb_3.png

I didn't change or set anything the day before. I'm not even sure what it means, but why should this appear for no reason?? It happened once before and I've had this computer two years.

I just said Cancel when it popped up.

I just have DSL with one computer, that's all.

Also:
Do you know why, when I hover over the networking icon, it says "Network 3"?
I've only ever had this computer on a DSL with no other devices at all.