Regardless of which OS you use you`ll generally need 2 NIC`s in the main internet connected machine for ICS and although i`ve never used a Windows ICS server i believe you`ll also need a Crossover cable rather than a normal straight through cable if there`s no switch involved.
For Vista
http://windowshelp.microsoft.com/Win...b14771033.mspx
And XP
http://www.practicallynetworked.com/sharing/xp_ics/
Welcome to CF btw
