Error - Ethernet card unplugged

Archived from groups: microsoft.public.windows.networking.wireless (More info?)

We set up a wireless network today and got it working...able to connect to
the internet, and able to play a game together on the two computers. Then
our Broadband internet connection went down. That is back, and able to
connect back to the internet on the computer that is connected to the network
wirelessly....however, cannot connect to the main computer.....in the network
connections window, when you click on the connection...it says "ethernet card
unplugged"....what has caused this to happen and how can I get it reconnected?