If the cards are installed, you're running TCP/IP, and on a network. Do a loopback ping.
Start/Run {ping 204.0.0.1}
If you get a reply, your protocol stack is ok.
Then ping your own ip address.
Start/Run {winipcfg} to get the address.
If you get a reply, you're connection to the network is ok.
Then ping an address across the network.
If you get a reply, you're good to go!
Dennis