The First Pixel

Possibility 1: Accidental Press FN + F6

On my Alienware 15 R1 laptop, the F6 key has no visible sub-function.  But, I accidentally press it often when attempting to increase the volume with FN + F5.  This shuts off the Windows Key… without any indication or warning.  I presume this is for gaming purposes, so that Windows does not throw you out of a game by a mistaken key press.

The fix:

Press FN + F6

FN + F6 toggles (enables / disables) your Windows key.

Possibility 2: Windows Key Lock

My Alienware m18 R2 has a Windows key on the right side of the space bar.  It has a neat little lock icon.  If you press this by accident, then any attempt to use Windows + D to see your desktop will be annulled.  At least this key lights up when pressed, like the Num Lock and Caps Lock keys.

The fix:

Press Windows-Lock key
(the right Windows key)