To shut down from the Start screen, press Windows-I, click Power, and choose 'Shut down' (or Sleep or Restart).
Several experts suggest adding a shutdown shortcut to the desktop or taskbar. Much has been made of the multiple clicks required just to shut down your machine. (If you're on the desktop, press the Windows key and then start typing.) For one thing, you don't have to click anything: just start typing to find and open a program, file, or setting. In fact, the Start screen is an improvement over the Start button. (My favorite free add-on for reverting to the old-style Windows interface is Classic Shell.)
The knee-jerk reaction of many Windows 8 newbies is to find a third-party add-on to restore the Start button.
Longtime Windows users have become attached to the familiar Start button in the corner of the Windows desktop. The Windows 8 Start screen beats the Start button The learning curve for Windows 8 isn't as daunting as some experts would have you believe. You can do with Windows 8 everything you could with previous versions, and then some. The best thing about Windows 8 is that the OS gives users more options than ever.