I don't know when this happened, but I used to have a slider bar at the botton of the left hand Navigation Pane in Windows Explorer. Now it's gone. If the the folder names are too long to fit in the pane, I'm just out of luck. Of course the full folder name will display if you hover over it, but that's only one name at a time.
So what governs whether or not that slider appears. On my laptop sometimes it's there and sometimes it's not. On my desktop, I can't seem to get it back at all.