Do you wish to host on lan (IPX) or internet (IP)
Internet you just follow onscreen menus to host, Router/firewall ports 17478 UDP and 4660 UDP
For lan on XP install IPX Protocol for your NIC and youre good to go.
Vist try this link
http://forums.microsoft.com/TechNet/...5104&SiteID=17
For Win7, forget it, only way I know is install XP virtual machine and then install the IPX protocol.
Hope this helps