   SetPixel
  I'm trying to use SetPixel() on another window.  It works fine if the pixel is on the right 1/3 or left 1/3 of the window but of the pixel is in the middle 1/3 of the window it doesn't work.  The really strange thing is that GetPixel() works for the entire window. Any help would be great, thanks.   
  SetPixel() isn't a standard C++ function. If you're using C++, which SetPixel() are you using? And if you're not using C++, which language is it?   ;  Sounds like clipping rectangle problem.But lacking code, OS, windowing system, it's a bit hard to say anything more useful.   ;  Would this be the Windows GDI function? clickyI don't know what would cause your problem however the documentation says the function returns the colour of the set pixel if it succeeds or else 1 if it fails so you might want to test to see what's going on.   