Gets the version of IIS.
Get-IisVersion [<CommonParameters>]
Reads the version of IIS from the registry, and returns it as a Major.Minor
formatted string.
Beginning with Carbon 2.0.1, this function is available only if IIS is installed.
Get-IisVersion
Returns 7.0
on Windows 2008, and 7.5
on Windows 7 and Windows 2008 R2.