Jesus guys, can we get down off our high horse for a minute and realise that this guy is asking a legit question. Quite probably he does not speak english as a first language, or he may be very young.
jrv, you are being a real pain in the ass. This is an internet forum, which means that people from anywhere in the world can join, so it is not suprising we get a mix of languages. Instead of moaning about it, enjoy the diversity.
You only joined a month or so ago, who the hell do you think you are to be restricting who can join?
Anyway, Ponftife, which units did you change, and how? the game will crash if so much as a comma is in the wrong place. Go back and try to find an error, or restore your backups and redo the process, slowly, stating the game after each step to check that what you have changed is right.
Also, if you right click your RTW icon on your desktop and open the 'properties' menu, add ' - show_err' (not sure if you need the _ or not). This switch will make a box pop up when you exit the game telling you of any errors, and where to find them. Its brilliant!