*sigh*

Can you people please read the previous posts in this thread before telling us that shaders don't work? There are two things that you can do to try and get shaders to work, which are as follows:

1. Turn off some of the options - specifically Liquid Blood, Soft Shadows and Reflections. This can help problems with shaders.
2. Buy a graphics card that supports OpenGL 2 shading. If your current card doesn't support OpenGL 2, then you can't use shaders. Simple as.
3. Also read the entirety of the first post on this thread and see if anything that Stilf has suggested helps.