Many people delete all icons on the desktop and after say hide and someone use some other way like right click(on the desktop) > personalize > change desktop icons(in right tasks pane) , and unselect  all check box icons. But you can hide only system icons with this way.

The simplest way to hide all desktop icons in windows vista.

Right click on desktop > View > and after then unselect Show Desktop icons
Enjoy you can hide all desktop icons in one seconds. If you want to show icons again just follow same process and select show desktop icons.

Tags: Customize window, Windows Vista