You are talking about mostly source code organization. Which every sane project does. So of course it is unlikely there is something that e.g. draws pixels in

You are talking about mostly source code organization. Which every sane project does. So of course it is unlikely there is something that e.g. draws pixels in the scheduler. But for example there is still some space reserved in the TEB for GDI things. And kernel space code for graphic purposes related to processes and threads -- a kind of graphic "kernel" if you want. I mean: you just cannot take Windows and change all the low level graphics support code to a kind of WinWayland or WinAndroid. Even just programming raw NT processes is not officially supported IIUC, so you are bound to using e.g. Win32, and there definitively are some pieces of code all over Win32 (and not just in trivially graphic related APIs) which is aware of the existence of graphics related features on the OS. So while it might be possible to recompile and/or rewrite parts of NT if you work at Microsoft to actually obtain a graphic agnostic OS (which is not even exactly what Nano Server is despite the re-engineering effort, because it is explicitly graphicless, not just graphic agnostic, and actually it now does not even exist anymore in a standalone form but only for containers, so you stick with your regular host kernel), that's not what I had in mind.