This message occurs when your NIC senses no connection. If you truly have a cable plugged in and the corresponding port lights on the router and the NIC are not lit, then your cable's integrity is the first suspect.
I have Hawking HWR54G router that displayes message "network cable is unplugged". I though that problem appeared because of my modem because router is relativeley new, however problem with router and not with modem. Is there something i should do in setting to fix that or something else. I updated my firmware so far and it didnt help. What should i do ? Thank you all !!