Physically look for chittin.key in the main game directory. It should be there. Also if your friend is trying to mod the games before starting them, tell them to start the games, make or import an existing character and get thru any opening cut scenes. All that is necessary to initialize the game and ensure that weidu can properly locate everything.
Sasha Al'Therin's Content
There have been 2 items by Sasha Al'Therin (Search limited from 05-June 23)