When it prompts on where to install simply point it to the Red Faction folder on your hard drive in order to find RF.exe, assuming it didn't find it automatically, if you don't know how to find that then right-click on your Red Faction in your Steam library, go properties, local files, go 'browse local files' and it'll take you right to it. Download the latest version of Dash Faction from here and install it (latest one will be linked on the 'Downloading the installer' section, accepting the prompts about it patching the game and just leaving that checked.
