Ah the joys of Windows 2000, if you're not plugged into at least a hub this wont work, as Windows says you're not connected, so the network never gets going properly for Sametime. There are a couple of easy fixes though:
1. Plug the machine into a hub
2. Make yourself a terminated crossover cable, this is what I do, here's what you have to do:
Get a network cable, cut it about 3 inches from the end, and expose the wires, now connect the following wires together:
1 to 3
2 to 6
You're basically creating a crossover cable but terminating it, when this is plugged in, it then makes Windows think it's connected to the network and you can start the Sametime server.
See:
http://www.whcs.com.au/services/network/xover.htm
Carl Tyler
http://www.instant-tech.com