Hello, I would like to play KoD but don't want to have to keep re patching the original game. Is there anyway I can have 2 versions installed of dishonored? One with the down patch and one with KoD?

After killing the twins and getting Emily unstuck when I got through the door on the other side it asks me if I want to go to the golden cat or stay on Clavering Blvd. It happens about 70% of the time and I have yet to figure out why. Any ideas?