In Windows XP and Vista operating system you can always minimize all the open windows and access your desktop using the show desktop option under the Quick Launch Bar. In case if you do not see the Quick Launch bar in your system, you can enable it by right clicking the Start button followed by selecting Properties from the menu list. This should display the Taskbar and Start Menu Properties dialog box. The Taskbar section provides the option for enabling or disabling the Quick Launch bar as show below.
Enabling Quick Launch Bar in Windows XP
Enabling Quick Launch Bar in Windows Vista