We've featured programs that close down non-essential Windows apps before, as well as ways to kill those regularly problematic apps. If you'd rather not install extra software, though, here's a way to create your own desktop shortcut to kill all running apps.
The process is pretty easy, though not for the faint of heart — this involves a command prompt command that will kill a whole bunch of programs, so make sure you know what you're doing before you start clicking away. In a nutshell, to create the shortcut, all you need to do is right-click on the desktop and hit New Shortcut. Copy and paste the following command into the popup box:
taskkill /F /FI "USERNAME eq geek" /FI "IMAGENAME ne explorer.exe" /FI "IMAGENAME ne dwm.exe"
Give it a cool icon (the above screenshot uses the C:WindowsSystem32imageres.dll icon) and put it wherever you want — on your desktop, in your taskbar, or in your Programs menu for safe keeping. Hit the link to read more on the ins and outs of the taskkill command and how to customise the shortcut for your own needs.