There are few different ways. You can do it right from your Halo game. When you are in the game menu just click on: create game > internet, then choose all your settings. You can also download the actual Halo server software and set that up on your own computer, which is much more complicated. You can also rent a server from a gaming company...that one is more complex to. The easiest way to do it if you only want to put one up temporarily is to do it through your Halo game menu.