check here for basics and its custom edition http://www.econsultant.com/cheats/h/halo-custom-edition.html
Ignore the links below if you don't have the custom edition.
Yes, there is a halo custom edition.
You can't cheat unless you have the Trial version of Halo Combat Evolved or you have the Halo Dev Trainer. You can also cheat on the edition to Halo Combat Evolved which is just a standalone version called Halo Custom Edition.*Please note that the cheats found online can only be used on the Halo Custom Edition and the Halo Combat Evolved Trial version. The retail version CAN NOT BE CHEATED on unless you have and are a modder.
Well, Halo Custom Edition is the multiplayer version of Halo Combat Evolved PC. It doesn't have a Campaign, by the way. If you want to get Halo Custom Edition, install the installer and use your Halo Combat Evolved PC Key. The main advantage of Halo Custom Edition is custom maps. Halo Custom Edition is currently in Version 1.0.9.620
DOWNLOAD IT ON FILEFRONT
Without hacking, I don't think you can. Halo Custom Edition is only PC
There is no Halo 3 mod for Halo Trial. Halo Trial is one of the hardest versions of Halo to mod. There are however, custom maps for Halo Custom Edition. To get Halo Custom Edition, you need to have Halo: Combat Evolved installed on your PC, you also need your CD key. You can download Halo: Custom Edition free.
no I'm afraid not, microphones don't have any use in Halo Custom Edition :(
No.
No!
google this halo custom edition download click first hit and look for download button done.