I have problem with Dell Latitude 5540 touchpad click. My my mouse won't click at all.  It will still move around the cursor on screen, and  it will still hover over clickable items properly, but, it refuses to click them.  This is true for  both the touchpad and the actual buttons themselves.  Initially right click wasn't working but now it wouldn't click at all although moves around, not sure how to fix this.  Any ideas?