Specially for touchpad users: if app "does not work" for you, please refer to this article: How to disable Metro edge swipes and touch charms bar gestures for trackpads (touchpads) in Windows 8.1 and Windows 8
Even if you recently switched to Windows 8.1, you probably noticed new features which allow you to disable top left corner, top right corner and skip Start screen to boot directly to Desktop. Those options are accessible inside properties of the taskbar:
However, there is still no way to rid of Charms Bar completely. For example, the bottom right corner can't be disabled using OS settings. So I decided to fix it and made this simple app: Winaero Charms Bar Killer
This app can kill the top left corner, the top right corner and the bottom right corner in Windows 8.1 and Windows 8. This can be handy for Windows 8 users too since they do not have options to disable those active corners.