Heroes of Might and Magic V - Patch 1.1 isn´t installing !

[Paco_BR]

I have the Heroes of Might and Magic V (EUA version), version 1.0 installed on my computer. When I try running the patch 1.1 (EUA version, also) it keeps saying that the game isn´t installed on my computer and quits.

I already reinstalled the game a couple of times, and it isn´t a cracked game. Now: how do I get to install this patch ?