Hi Xavi, sorry for the delay in replying.
I have not had anyone say they have had trouble with windows 8 before but I am not sure if any current users are using windows 8 so I will look into it. I would guess the latest DirectX would stay compatible with DirectX 8.1 for some time yet. I have DirectX11 installed on my computer but I am using windows 7 Perhaps there is some dll file on my computer that does not come with the latest DirectX11 run time libraries. I am currently working on an OpenGL version of seamless so that it can run on other operating systems and have been thinking about writing a version of seamless for Directx11 too. I am hoping to get access to a computer that has windows 8 sometime in the not too distant future so I should sooner or later find a solution to your problem. Thanks very much for the feedback and very sorry for your inconvenience, best wishes, thyme