I have a dual monitor setup involving a laptop and an external monitor and of course they are different sizes ( laptop-1366 x 768 and external-1280x1024 ). I have noticed that while my laptop monitor is 768 pixels high, the virtual display is much bigger. In this screenshot of my display you can see on the left screen a light area which is the actual monitor size. The dark areas which appear at the top and bottom of the screen aren't visible on my physical monitor, but the OS continues to place icons there and some applications even start there. Does anyone know how to get rid of this surplus space ?
Set the higher resolution monitor to be your primary monitor. Steps for this vary depending on what driver you're using, if it supports xrandr, whether or not you're using xinerama, and if you're tweaking your xorg.conf among other things.
So no step by step. You can get all your icons on your desktop that way though.