I have bought You already should have the game... You can't have rotw without bfme II.
First you have installed Bfme II. Afterwards you have installed rotw.
You have done those two steps already, as you wouldn't be able to play rotw otherwise. (its just an addon, not a 'stand alone'-game)
Therefore you have those two folders already on your pc.
I can't give you a link, as I have bought the dvd and haven't downloaded it. (which is illegal, if you don't have bought it)
Just search on your computer for the folder "The Battle for Middle-earth (tm) II" and you should find it.