How to re-create the Show desktop icon on the Quick Launch toolbar

To re-create the Show desktop icon by yourself, you may follow these method:


Method 1: Manually re-create the Show Desktop Icon

1. Click Start, click Run, type notepad in the Open box, and then click OK.
2. Carefully copy and then paste the following text into the Notepad window: [Shell] Command=2 IconFile=explorer.exe,3 [Taskbar] Command=ToggleDesktop
3. On the File menu, click Save As, and then save the file to your desktop as "Show desktop.scf" (with quotes, in order to prevent Notepad from appending .txt extension) The Show desktop icon is created on your desktop.
4. Click and then drag the Show desktop icon to your Quick Launch toolbar.

Method 2: Using the Regsvr32 command

1. Click Start, Run and type the following command:
regsvr32 /n /i:U shell32.dll
2. The Show Desktop icon file should be available now.

Method 3: Copy the file from another user account

Every user account will have a copy of Show Desktop.scf file. Search for the file named Show Desktop.scf in your computer by logging in as administrator. Copy it to your user profile path here:

%Appdata%\Microsoft\Internet Explorer\Quick Launch

(Type the above path in Start, Run dialog)

Reference:
http://support.microsoft.com/kb/190355
http://windowsxp.mvps.org/showdesktop.htm