Cfs Multiplayer question

I have a friend who has cfs by way of a crack file. I used my cd to install the game on his computer and gave him the crack file. Well we can't connect to multiplayer by ip so I tried the zone and that didn't work either. I then tried the crack file on my computer and I got through but he can't. I thought it may be because of a firewall but he had it turned off. Any ideas why we can't connect? I have windows 98 and he has xp but that shouldn't cause any problems should it? ???