[andrewas]

BG2 isnt the greatest of multiplayer games, and it lacks a server-finder. You can use gamespy, but the few servers Ive joined on that were full of hackers and PKers. Which leaves us with doing it the hard way.

First thing you need is the IP address of the host computer. Assuming a standard connection, go into start->run->command. Type "ipconfig". Somewhere in there will be a line giving your Ip address. If theres more than one such line, the one you want isnt in the 192.169.x.x range, nor the 10.x.x.x range. If you dont have any addresses that arent in those two ranges, you have a LAN with router and things get complicated.

Now start BG2 on the host and start a multiplayer game.

Start Bg2 on the other machines and join multiplayer game over TCP/IP. When it asks for a server address, give it the IP of the host. Barring inconvinently placed routers and firewalls, the client should find the host and you should be able to join the game.