After messing up my game several times with multiple patches mixed with various incompatible mods, the safest course is to make a copy of your entire games folder, & install the patch you want to use into one of them, that way if it all goes belly up you don't have to reinstall everything, you can just rename your original folder & retain all your save games. Of course you need some HD space but it saves alot of trouble. Currently have 5 different versions of RTW installed which I play independently of one another.