Sneezemeat

"You don`t install it in Steam at all . First create a folder in Documents and name it to Witcher 2 then create another folder inside the Witcher 2 folder and name it UserContent . Uninstall FCR 2 from control panel>Programs and Features then reinstall FCR 2 pointing to your Steam installation but go no further than Witcher 2 as the last entry . Start witcher 2 launcher and then close the launcher . This gives the config folder and downloads folder . Now click the launcher again and click the mods tab , select the boxes for FCR 2 and then save and run or save and exit and you should be all set ." Taken from RedKit Moderator here: CdProjektRedForums