Yes sometimes the Nocd patches are in fact only 'Fixed exes' meaning you still need to use a backup copy of the original game disc! What is the use of this I hear you saying? Well, it allows you to store the original away in a safe place, so it doesnt accidentally get damaged, and play from a copied version!
(I dont have the game myself but just letting you know how it is with some of the sometimes falsely labelled Nocd patches!

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