H1 and Halo Custom edition name: madkiller92
xfire:madkiller92
Maybe you don't have the latest patch?
http://www.bungie.net/images/games/halopc/patch/halopc615.zip
When you get it, open the first file, then open the "Halo PC" file, and you will see there things. Then click on run, and go to C:\program Files\Microsoft games\Halo, and click and drag the items from the "halo PC" files into there (overwrite the old ones). Then, launch halo, and under the "join game" section of multiplayer, make sure your clicking on internet AND NOT LAN.
Also, make sure your internet is working, otherwise you won't get any severs. Try restarting your PC (and the router your wireless card runs on if you have a wireless card) if none of this works.
[Edited on 07.09.2008 8:30 PM PDT]