Changing Halo Cd Key

[forgot]

Yup, ive got another halo cd key (proper) and I want to change it to this one so I can play lan, but how do I change it? Is it something to do with regedit? Thanks

[oreoman]

check yur pm

[Gre1]

Do u have the real game, if not halo's cd key is whatever u type.

[forgot]

I have the real retail game installed but I took the game back so I need to dfind a way to change the cd key without having to install the game again. thanks

[muchspl2]

why don't you post the anwser, people I know asked this very question, help everyone out :(