The keyboard shortcut to close open windows
or Windows itself is ALT + F4.
Shut down Windows
Click on the desktop and press ALT + F4 at
the same time. This will bring up a dialog
box asking if you'd like to Stand by, Shut
down, Restart, or Restart in MS-DOS mode.
Chose one and press OK.
Close a window
Find a program or file you'd like to close,
make sure to save anything you're working
on, and hit ALT + F4 at the same time. This
will close the topmost window that is open.
Continue closing open windows by activating
them with a single-click and pressing ALT +
F4.