I am not some computer wise person, but I don't understand why you can't do a full installation. Doesn't your pc meet with the minimum installation requirements? Is that particular cd scratched or something? And finally, you do have a legitime copy of the game, don't you?
• "You cannot pass."..."I am a servant of the Secret Fire, Wielder of the Flame of Anor, You cannot pass. The dark fire will not avail you, Flame of Udun. Go Back to the Shadow! You cannot pass."
Gandalf the Grey