fx composer requires a .net framework development kit, and a gpu at least of the nvidia fx generation (DX9). the CgFX viewer is a nice tool to view cg/fx shaders, and play around with them, but they aren´t easy to get to work with GStudio. nevertheless, i recommend it (the fx shader base is a must): http://developer.nvidia.com/object/IO_CgFXViewer.html