dgbarar:
Hello and welcome to the forums;
When you are connected directly to the cable modem,
Can you open the Network and Sharing Center and click on the public network and change it to work or home?
Can you use the ipconfig /all command from a command prompt and determine what IP addressing scheme your wired network card is receiving from the device?
Sometimes you'll get the unidentified network issue if the IP addressing scheme is missing a default gateway.
Sometimes when changing devices that are plugged into the ISP's modem you may have to restart the modem inorder to receive new DHCP information, as the old info is associated with a different MAC address.
If it's an ADSL connection using PPPoE, you may have to embed the username...