I have an Intel HD graphics card. By the way, sorry for the late response.
Oh, then this is the expected behaviour. TexGraph is far from being compatible with such graphic chip, it requires something like an Nvidia or ATI graphic card powerful enough to run it. Intel HD Graphics chips lacks from a complete OpenGL implementation, so TexGraph isn't prepared to run there, and it will probably never be.
Thank you for your response and apologize for the inconveniences.