you can point at the very top of the task bar, you will see a double arrow, when you have the double arrow displayed, left click, hold the left button down, drag the taskbar towards the bottom of the screen, let go of the left button. This will only adjust the size between 1 inch and 1/2 inch tall.
There is another cool trick, hide the taskbar, but it will pop up only when you point at it.
point at the taskbar
left click on properties
check mark the box that says: hide the taskbar
click apply, click OK
Now when you click on the desktop, the taskbar will hide
When you point at the bottom of your screen, the taskbar will pop up and show.
That way the taskbar is hidden until you use it.