In Windows 8.1, if you right-click on the Window icon in the taskbar, you see a list of “Power User” commands -- the so-called WinX commands. Two of the commands start a command prompt, which is handy for DOS-style access to your machine.
In the Navigation Properties dialog, if you check the box marked Replace Command Prompt with Windows PowerShell in the menu when I right-click the lower-left corner or press Windows key+X, the Command Prompt item in the WinX menu is replaced by PowerShell, and Command Prompt (Admin) is replaced with PowerShell (Admin). If you’re a PowerShell user, that may be helpful.
I have no idea why Microsoft didn’t put all four commands on the WinX menu.