network problem

hi i tried to do a lan game with my two computers but for some reason my "network setup" option in the multiplayer is disabled! does anybodyu know how to fix this? i also tried to do direct internet connection and it's not wokring.......i know the internet works cuz i play other games with the two computers but just not with live 2000....if anybody knows the solution to this please help me........thank you very much!

live 2000 fan