The official website for The Settlers of Catan

Question about Technical Questions I have an old computer. Will the program run on it too?

Answer

To test whether the performance of Catan – Cities & Knights is sufficient when running on your system, you should try the free trial version. Furthermore, you can optimize the program for older and less powerful systems via the game options:
On slower computers the resource or dice animation may become jerky. If this bothers you, you can switch off the resource animation (e.g., during production) in the options menu. The options menu may either be accessed via the main menu or, during a game, via the “Options” button in the upper button bar. If you would like to display message boxes instead of animations, please set the option “Animation” to “OFF.” In addition, you can also switch off the water animation via the option “Water” and thus improve performance.