There might be some previous thread you don't refer to, but that is essential to solving your real problem. Sounds like ICS (client/server)? With a DCC (Direct Cable Connection)? But could be quite something else, of course.
No connection at ALL might simply mean the wrong cable. For a DCC (between parallel ports, or between NIC's) you need a 'cross cable' not a straight one. Or it's a failing NIC. Or no drivers installed. Or wrong settings in a few Control Panel screens.
Did you try the Network Troubleshooter? It will guide you through the common causes.
Hope this helps.
Kees

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic