If the Show Desktop icon been deleted from your Quick Launch bar, it can be quickly restored by performing the steps provided in this tech-recipe.
1. Open Notepad.
2. Copy and paste the following:
[Shell]
Command=2
IconFile=explorer.exe,3
[Taskbar]
Command=ToggleDesktop
3. Save the file as showdesktop.scf to your desktop.
4. Drag the created file to the Quick Launch area of the taskbar.