The Quicklaunch toolbar is an optional toolbar with XP
that usually sits on the taskbar to the right of the Start
button. Above it has 4 icons on it. These may be
customized. A single click on any icon in the
Quicklaunch toolbar will open a program. The button
doesn't change color or become highlighted as with Windows
7. Instead a rectangular label appears to the side, to
show that the program is open.
The Show Desktop icon in XP is the first icon in the
Quicklaunch toolbar above.