Game progress is typically stored in %USERPROFILE%\Saved Games\Risen3\SaveGames\ .
Windows 7/8/10 (64-bit versions only for the Enhanced Edition). Risen.3.Titan.Lords.GOG.part2.rar
It is a .rar file, part of a split set. You generally need all parts (Part 1, Part 2, etc.) in the same folder to successfully extract the installer. Risen.3.Titan.Lords.GOG.part2.rar
You can adjust settings like FOV or windowed mode in the ConfigUser.xml file located in %LOCALAPPDATA%\Risen3\Config\ . Risen.3.Titan.Lords.GOG.part2.rar