Desktop Ruined After Reboot and Other Problems

I have no idea what happened, but now, my desktop has NO icons, and if I click on the Start Button, what I get is the desktop theme with the start button menus, etc., superimposed on the theme.

Just found something else: I clicked on the "minimize to desktop button" while writing this, which took me to the `false desktop,' and to return to this forum I had to click on the Start Button; clicking on the task bar icon for Firefox does nothing, nor does doing that for other applications either. In addition, the sqaure at the top right-hand corner for applications, that should reduce the size of the open window no longer does anything.

A short while later: I can get back to Firefox, etc., from the task bar icons, but have not quite figured out just how many clicks, etc., make it work.

Windows Key + D no longer does anything. It is as though I don't really have a desktop. (I have tried the shortcut keys to cycle through virtual desktops, which does not show me anything.

More discoveries: If I minimize an application to the task bar, then click on the start button, I can then return to the app by a single click on its task bar icon. When I click on the start button, it now always opens with just the Life and Play displays, no left-hand column. (I don't remember the name of those two `boxes.') I have to click on the start button's top-left icon to bring up the column with apps, access to Settings, etc.

Good Grief: Don't ask why I happened to look at the Settings module that includes an option for Tablet Mode. Suffice it to say that changing that from on to off, a setting when I had not turned it on, has restored matters to where they were before I rebooted.

Truly odd, along with just about everything else. Perhaps my odd experience will help anyone else who encounters what I met.