The following windows key shortcuts should be helpful for every day use.
 + L |
Locks your PC instantly |
 + D |
Show the desktop |
| + up arrow |
Maximise the window |
| + down arrow |
Minimise the window if at normal size already, if the window is at maximum size it will reduce it to normal size |
| + M |
Minimise all windows |
| + E |
Open up computer |