To make the Windows taskbar reappear, point the cursor arrow to the spot on the screen where the taskbar last appeared. The taskbar should then reappear.
If the most recent position of the taskbar is unknown, begin by pointing to the bottom edge of the screen. If this doesn't work, pointing to the side edges of the screen or the top edge should make the taskbar reappear. It may be necessary to point the cursor to the very edge of the screen so that it almost disappears; this should enable the function that makes the Windows taskbar reappear. Alternatively, turn off the taskbar auto-hide feature from the Control Panel screen.