The installer also requires you to have a legal copy of Call of Pripyat installed on your system, this doesn't matter if it's GoG, Steam or boxed versions of the game.ĬoC is a standalone and use it's own engine, don't install it over CoP.
It is not recommended to have your install located in Program Files where your OS is installed. Simply run the executable and follow the steps on screen. A: Call of Chernobyl is packaged inside an installer.