How do i change the starting positions for the icons?

Hi 

I'm using vista with the sidebar on the left because i like to have rainlendar on the right  

When i download a new file and save it on the desktop, its icon appear as usual on the top left corner...under the sidebar.

I have a 15" monitor and i would'nt like to set the sidebar always on top because i want to use the windows in full screen. 

Is it possible to change the starting position of the new icons in the desktop? Is there a registry setting that i can change or do have i to use a software like desktop icon toy?

Thanks