Hello Lohnennicht,
DirectX Shaders (experimental) is the option enabling DirectX 9 with pixel shaders for applications that require accelerated 3D graphics support. If your applications require DirectX 8.0 or earlier, you needn't select this option.
DirectX 9 with pixel shaders is supported experimentally. And it is only available for Windows XP and Vista as Guest OS.
Best regards,
Xenos