Enabling cheats and all the cheats!:
In order to make the codes work, you must add the following line to the bottom of the hitman.ini file: Enableconsole 1
Once you do that, run the game. When playing, press the "~" key, and a gray box will slide from the top of the screen. You can then put in any of these codes.
invisible 1 Invisibilty
god 1 God Mode
giveall All Weapons
infammo Infinate Ammo
Put in Kim Bo Kastekniv for your name