Two questions I get a lot on Windows 8:
1. How do I close an application?
2. How do I shutdown Windows?
#1 – There are 3 easy ways:
The first is the coolest. Click and hold in the area where you’d expect a title bar to be, then drag all the way down to the bottom of the screen.
The second is to press ALT+F4 on your keyboard.
The third is to move your pointer to the top left of the screen, then close the app from the open apps list running down the left side of the screen.
The fourth is to end the task from task manager.
2. How to shutdown Windows:
Option 1: Press Windows Key+c to bring up the Windows Charm, then choose the shutdown option in the bottom-center of the charm.
Option 2: Move your pointer to the top-right pixel of the screen, wait a moment or two for the charm to display, then choose the shutdown option in the bottom-center of the charm.
Darren Myher's Blog 