Whenever you open a window, a button corresponding to it will appear in the taskbar. It disappears when closing the window.

Within the taskbar contains the Start menu and system tray, where you'll see a clock. Other icons can appear and disappear at any given moment, showing the status of background activities. For example, the printer icon will indicate when the printer is active or when you send a file to the printer, and disappears when printing has finished. You'll also be reminded in the notification area when Windows updates are available for download.

Windows XP keeps your taskbar organized by combining buttons into one when a lot accumulate. For instance, buttons representing e-mails are automatically grouped together under a single button. Clicking the button allows for easy selection for the message you're looking for.