Add XP "Show Desktop" Icon to Windows 7 Taskbar

Window 7 has a small rectangular blank button next to the clock to show desktop.
        
It is possible to add a "Show Desktop" icon which is old Windows XP style to the taskbar. The following steps can tell you how to pin the "Show Desktop" icon to the taskbar.  

1. Select a shortcut icon which you don't want to see in the taskbar, right click it and pin it to taskbar. I take CCleaner icon as example.
   
   
2. Open a new text file or Notepad. Type the following sentences and don't change any format.
   [Shell]
   Command=2
   IconFile=explorer.exe,3
   [Taskbar]
   Command=ToggleDesktop
   
3. Click File -> Save as, and select a location to save this file. Then type "Show Desktop.scf" in "File name", and select "All files" as the save type. Finally click on "Save" button.
   Note 1: You must save it into the following directory.
   C:\Users\USERNAME\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar
   Note 2: USERNAME is the account you use to logon your computer.
   
   
4. Right click on the icon which pinned earlier, and right click again on the name in the list. Then select "Properties" to open a new window.
   
   
5. In the "Shortcut" tab, change the Target to the following location.
   C:\Users\USERNAME\AppData\Roaming\Microsoft\Internet Explorer\Quick Launch\User Pinned\TaskBar\Show Desktop.scf
   Note: USERNAME is the account you use to logon your computer. Remember change the USERNAME in the Target.
   
   
6. Then click on "Change Icon" button to change the icon. Type %SystemRoot%\system32\imageres.dll in the blank next to "Browse" and press "Enter". Then select the Show Desktop icon as shown. It locates near the middle of the list. Click "OK" button to save your changes.
   
   
7. Now the icon you pinned to taskbar can be used to show desktop, but the icon is not changed until you restart your computer or reload explorer.exe.
   After doing this, you can see the Show Desktop icon in the taskbar.
   

You can also press "Windows key+D" to open your desktop.