The proper way of shutting down Windows 8 is through the Charms menu, which can be opened by moving your mouse to the top right corner and then sliding down (a horrible gesture), or hitting Windows Key-I (much better). Then just click the Power button and select Sleep, Shut Down, or Restart.
The other option, which I prefer, is simply going to the Desktop and hitting Alt-F4. This pops up the old-school (Windows XP/2000) Windows Shut Down dialog. This method is particularly useful on dual-screen setups, where you will often have the Desktop visible on one of your monitors.
The fastest option is to create a Shut Down shortcut and place it on your Desktop taskbar and Metro Start screen. Right click your Desktop, click New > Shortcut, and then type in:shutdown /s /t 0. (Don’t include the period. That’s a zero, not the letter O.) You can then right click the new shortcut and Pin to Start — and then you can drag it onto your taskbar. Clicking the shortcut will shut down your PC immediately.
An easy way to bypass the Windows 8 Start screen after log-in
For some unknown reason, Microsoft does not provide a configuration setting for bypassing the new Windows 8 Start screen. You would think that, at least on non-touch-enabled devices, Windows 8 would default to the Desktop — but alas, Microsoft in its infinite wisdom thinks that Metro with a mouse and keyboard is a joy to use (it isn’t).
Fortunately, with a little bit of hacking, there’s a very easy way to bypass the Start screen after logging in. Hit Start, type schedule, click Settings, and open “Schedule tasks.” Click Task Scheduler Library from the left pane, Create Task on the right pane, and give it a name like Boot to Desktop.
Then head into the Triggers tab, click New, and then select “At log on” from the drop-down. Click OK. Head to the Actions tab, click New, and then simply type explorer into the Program/script text box. Click OK, OK again, and you’re done. Restart (or sign out) to test it.