Hi there,

The reply of some users did work for me on windows. Thank to all replies.
However, by running the code below, I have a window, in which part of the
top of it is used by the window bar. Do you know how to solve this?

Graphics.open_graph "300x300+0+0";
Graphics.fill_rect 0 0 100 100;
Graphics.fill_rect 200 0 100 100;
Graphics.fill_rect 100 100 100 100;
Graphics.fill_rect 0 200 100 100;
Graphics.fill_rect 200 200 100 100;
Graphics.read_key ();
Graphics.close_graph ()

Cheers,
Marcel