I've had this happen with NICs before. Once Windows sets it up you can remove it and then when it reinstalls it sees it as "NIC 2". My guess is that you unplugged your router and when you hooked it back up it saw it as a new one. It's been a while, but as I recall I had to burrow pretty deep into the registry to clean it all out, then let Windows detect it as a brand new connection. Now when that happens I just ignore it as not being worth the trouble.