Can't connect to internet, says ethernet cable unplugged but it is

Hey all,
All of a sudden my Mini won't connect to the internet. I checked network settings and it said cable unplugged or not responding at the other end.
I re-set the modem, unplugged and plugged the cables back in, even bought new cables and it still doesn't work.
Time Warner checked on their end and said the modem is receiving the signal, went through the re-set process again and still nothing.
I checked system information and when I click on ethernet card it says:
"this computer does not appear to have any PCI ethernet card installed."
Are they referring to the card than came built in to the computer or were they looking for a different card?
Does this mean my ethernet card is shot?

Thanks for any help. Time Warner is coming tonight but if it's not the modem it will be a waste of time.