Windows 8 Closing an app
Windows 8 apps don’t have close buttons, but this isn’t the issue you might think. Apps are suspended when you switch to something else so they’re only a very minimal drain on your system, and if you need the system resources then they’ll automatically be shut down. (Their context will be saved, of course, so on relaunching they’ll carry on where you left off.)
If you want to close down an app anyway, though, move the mouse cursor up to the top of the screen. When it turns from the regular mouse pointer to the icon of a hand, hold down the left mouse button and drag it down the screen. Your app should shrink to a thumbnail which you can drag off the screen to close it.
If that’s too much hassle, then simply pressing Alt+F4 still works.
And when all else fails then press Ctrl+Shift+Esc to launch Task Manager, right-click something in the Apps list and select End Task. Beware, though, close something you shouldn’t and it’s easy to crash or lock up your PC.