The touchpad on my Dell Latitude 5580 is not working. When I disconnect my mouse, my cursor disappears. I have looked in the device manager, and the touchpad is not present. Not even when I select "show hidden devices". I have tried to install the driver from the Dell website, but that does not help. 

The rubber knob thing in between the keys is not working either. If I don't have a mouse connected, I have no way of using my laptop.