It is the Drafting tab, fourth from the right…
Ok, those viewport tabs look hideous. What can you tell us about the system you are running Rhino on. Specifically, the make/model of the video card and the screen resolution you are using. A screen shot of your OpenGL page (Tools -> Options -> View -> OpenGL) might be helpful too.
i got it thanx for the reply ,i dont know how to take my question of the
forum, the problem was i accidentally changed the font color and the
background color to the same color, took me about an hour to figure
out,thanx for the reply