Windows PowerShell is a command-line shell for Microsoft Windows that is used for system administration. It uses cmdlets (commandlets) that are .NET classes to perform administrative tasks, and can access COM and WMI for local and remote administration. PowerShell can also be embedded within applications to make use of its abilities. PowerShell originated in 2006 when Monad (Microsoft Shell) was renamed to Windows PowerShell.
In the above picture is an example of PowerShell running in Microsoft Windows 7 Home Premium.
Tip: Users running earlier versions of Windows, such as Windows XP and Windows Vista, can also download PowerShell.