By design, Metro apps in Windows 8 are not meant to be shut down, because you wouldn’t normally shut down apps on a phone or tablet. Therefore, you won’t find an exit command or a close button, like you’re used to.
However, if you really want to shut down a Metro app, there are a few ways you can do this.
Use the Keyboard to Close a Metro App
The quickest and easiest way to shut down a Metro app is to press Alt + F4. This terminates the currently running app immediately.
Use the Mouse to Close a Metro App
To shut down the currently running Metro app using the mouse, click and hold on the top edge of the app, or the screen, and drag down to the bottom edge of the screen. The app becomes a smaller window and is dragged off the bottom of the screen.
Use the Task Manager to Close a Metro App
The most powerful way to shut down a Metro app is using the Task Manager. Press Ctrl + Shift + Esc to bring up the Task Manager. Find the app, select it, and click End Task.
NOTE: For IE, there may be two versions of it running. The image below shows two tabs open in the desktop version of IE (with the round icon), and the Metro version of IE open as well (with the square icon).
Minimize a Metro App
If you want a Metro app out of the way, but you don’t want to close it, you can minimize it. One way is to move the mouse to the extreme, lower, left corner of the screen to show the mini Start screen button and click it. The Start screen displays, but the app is still running in the background.
NOTE: When clicking the mini Start screen button, be sure to keep your mouse button in the extreme, lower, left corner. If you move it away slightly to click on the button, the button may disappear.
Another way is to press Windows key + D or Alt + Shift + Esc to go back to the desktop. Then, go back to the Start screen by clicking the Start screen button in the extreme, lower, left corner of the desktop or press the Windows key.
Close a Minimized Metro App
Use your mouse to close a minimized Metro app running in the background. Move your mouse to the extreme, upper, left corner of the screen until you see a thumbnail of your running app. Right-click on the thumbnail and click Close.
NOTE: The thumbnail displays the last app that was active. If you just switched from the Desktop to the Metro screen, the Desktop shows. If that happens, open the app again from the Metro screen and close it using one of the methods mentioned earlier in this article.
Closing and minimizing apps in Windows 8 may seem complicated, but after a while you can get used to it.