Well, the FX Composer 2 needs you to have a rather new Video card installed. Something like GeForce 7800GS or better that has good Shader version 3.0 support.

You can find more info at this NVidia Forum.

FX Composerr 1.8 is really nice though even if you have to modify the shader code generated before using it in 3DGS.
cheers,
tindust