It is quite easy to remove icons from toolbars, simply without realising that you have done so. Once particular icon that regularly gets accidentally removed is the Show desktop icon in the Quick Launch Toolbar. Here is how you can replace it.
First you need to enable the Show Hidden files and Folder option. to do this proceed as follows:
1/ Click the Start button.
2/ From the Start menu click Control Panel.
3/ In the Control Panel window click the Folder Options icon.
4/ Once the Folder Options windows opens click the View tab.
5/ Scroll down the list of folder options until you come to the Hidden Files and Folders Option.
6/ Click on the radio button next to the Show Hidden files and Folders option to enable this option.
7/ Press Apply followed by OK to close.
1/ Open Windows Explorer.
2/ From the menu in the left hand pane of the Windows Explorer window click the + sign next to the C: drive.
3/ This will expand the menu.
4/ Next click the + sign next to Documents and Settings.
5/ From the expanded menu click the + sign next to the folder containing <your name>.
6/ Again from the expanded menu click the + sign next to Application Data.
7/ Now click the + sign next to Microsoft.
8/ Now click the + sign next to Internet Explorer.
9/ Finally click on Quick launch.
10 Locate the Show Desktop icon and Right click on it.
11/ From the drop down menu select Create Shortcut.
12/ When the shortcut has been created Drag it to the Quick Launch Toolbar.
13/ Once on the Quick launch Toolbar you can Right Click on the icon and rename it to Show Desktop.