If you had the show desktop icon at one time and now it's missing. This is how you restore the link onto your desktop.
WinXP
type Start -> Run -> type regsvr32/n/i:u shell32.dll and press Enter
a dialog should tell you that the process succeeded.
Now you need to restore the icon in the toolbar
To restore it either reboot or do the following select Start -> Run -> type as is with quotes "%appdata%\microsoft\internet explorer\quick launch" and press Enter
Now it will show in the Quick Launch bar.
In Vista
download the file labeled 'ShowDesktop.zip' from HowToGeek.com and then open the file and drag it to the Quick Launch bar.
