I think you should ask why was halo custom edition created because the reason people download the maps is because they can have fun on halo with other people across the world. halo custom edition was created for that purpose and it only plays maps that you download not the normall halo. your asking why do you it is more like your asking why do I.
Halo Custom Edition is FREE.You can download Halo CE from http://hce.halomaps.orgTo install Halo CE you need the original Halo Combat Evolved game.
You install it then play it from the shortcut.
DOWNLOAD IT ON FILEFRONT
google this halo custom edition download click first hit and look for download button done.
You can download a demo version of Halo: Combat Evolved for free on the internet. There is also the Halo: Custom Edition, but this requires the CD Key of the full version of Halo: Combat Evolved installed on the computer you install Custom Edition on. Custom Edition is free, and allows for the use of user-created maps. It does not include the campaign though.
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
MAPS
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.
you go on the website www.halomaps.org
Have you pirated the game? If you have, it won't install. If it's a legitimate copy, make sure it's installed in the "Microsoft Games" Directory.
I would assume you install it.
Pipedream for Halo Custom Edition features mechs.