PowerShell versions
Let’s take a closer look on how to identify the powerShell version installed. We can check the version by using $psversiontable or get-host ($psversiontable is first available from version 2.0). Version 1.0 Version 1.0 is available for Windows XP, Windows Server 2003, Windows Vista and Windows Server 2008. http://support.microsoft.com/kb/926139