For supporting all features and effects, the engine requires a recent 3D accelerator and DirectX 9.0c or better. Please note that there are 3 DirectX9 versions - 9.0a, 9.0b, and 9.0c - that are mutually incompatible. DirectX 9.0c is the most common one and comes with the Service Pack 2 for Windows XP. You can use the DxDiag tool for checking which DirectX version is installed on your PC. You can download a redistributable DirectX 9.0c setup for you and your customers from http://server.conitec.net/down/directx9_redist.zip.
3D accelerators differ in features, speed, texture memory, maximum texture size, and in the reliability of their software drivers. Depending on the characteristics of the hardware, the engine uses different algorithms to generate textures, shadows, and other effects. The engine always tries to squeeze the best performance and image quality out of the hardware. An indicator for the performance of your hardware and the maximum texture size is the message in your starting window.