A nice feature of the Taskbar is that you can move it to any of the four sides of the Desktop, and also you can resize it (by dragging the border) anywhere from half the screen to almost nothing. Curiously, when some people resize it to nothing, they panic and complain that their Taskbar has gone completely. Not so! The Taskbar's border will always be there.
Look carefully at the edges of the Desktop, especially on the side you last saw your Taskbar. There will be a thin gray line (or whatever color the Taskbar happened to be.) This is the Taskbar's border. If you point to the border with the mouse, the mouse cursor will change to a double-pointed arrow - of which you can only see half of it (the other half being off the screen), like so:
You can then hold the mouse button down and drag the border inwards to the size you want your Taskbar to be.