you may ha ve to disable the windows firewall"for hamachi" and in some cases you may not be able to use a router or wireless connection to play the game.
（我试验过，防火墙和杀毒软件并没有影响，我的是nod32）也许你需要在hamachi网络上禁用防火墙，并且，根据一些人的反映，你可能无法使用路由或者无线连接玩这个游戏
disable windows firewall "at your own risk".
关闭防火墙的风险将由您自己承担
http://www.xpmaximized.com/archives/...-firewall.html
以下是vista的，不好意思，没有图，只好直译
-------------------------------windows vista----------------------------------
a. click the startmenu, type in ncpa.cpl into the search field, click enter
a 打开开始菜单，在搜索区域中打“ncpa.cpl”不带引号，然后按回车
b. in the new window, click "alt" on your keyboard, click the advanced tab, then click advanced settings.
b 在新打开的菜单中，按住“alt”再点击高级选项，然后点击高级设置
c. in the adapter/bindings tab under connections, use the up/down arrows to relocate the "hamachi" network connection to the top. this will make rsv2 choose the hamachi network connection as default.
c 在连接的网卡选项卡下，使用上下箭头重新安排hamachi网络，使其置顶，这会使维加斯2选择hamachi网络为默认网络
4. now you need to select a hamachi network to join other players that are playing rsv2
第四步 现在，你只需要选择一个hamachi网络来参加或邀请他人进行游戏啦
下面就是一些如何加入hamachi网络，和一个老外服务器的网址了，如果大家有需要我再翻译吧
5. visit http://www.planethamachi.com/net_public.php
6. select a network that is playing rsv2 and select the "join" button at the bottom of the screen
7. a download window will pop up. tell the download window to open the file with hamachi.
now this network will be added to your hamachi program.
8. now you can either host a game of rsv2 or try to find an existing server by searching the lan sections of story mode,
versus, and terrorist hunt.
9. if you can’t find a game, you can set up a game with people by messaging with the players in the network.
