Why is Powershell 2.0 installed in the same location as Powershell 1.0?

Question

Does anyone know why Powershell 2.0 is installed in C:\\Windows\\System32\\WindowsPowerShell\\v1.0 on a Windows 7 box?

Answer 1

I just think that, at the very begining, Microsoft team plan to deploy PowerShell versions side by side, just as it's done for the Framework .NET versions. But with the time they decided to support only one PowerShell at the time.

There something even more strange when you use the -version parameter of the command line to choose version 1.0 the var $PSVersionTable is present with PSVersion valued to 2.0. $PSVersionTable is not present in PowerShell 1.0

C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC>powershell -version 1.0
Windows PowerShell
Copyright (C) 2009 Microsoft Corporation. Tous droits réservés.

PS C:\Program Files (x86)\Microsoft Visual Studio 10.0\VC> cd \
PS C:\> $PSVersionTable

Name                           Value
----                           -----
CLRVersion                     2.0.50727.4952
BuildVersion                   6.1.7600.16385
PSVersion                      2.0
WSManStackVersion              2.0
PSCompatibleVersions           {1.0, 2.0}
SerializationVersion           1.1.0.1
PSRemotingProtocolVersion      2.1

If you have a look on var $host which exists on both versions

PowerShell V2.0 (vith version 1.0 or 2.0)

PS > $host
Name             : ConsoleHost
Version          : 2.0
InstanceId       : b6ae2582-c1f4-422a-b057-16458b387f7d
UI               : System.Management.Automation.Internal.Host.InternalHostUserInterface
CurrentCulture   : fr-FR
CurrentUICulture : fr-FR
PrivateData      : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy
IsRunspacePushed : False
Runspace         : System.Management.Automation.Runspaces.LocalRunspace

PowerShell V1.0

PS > $Host
Name             : ConsoleHost
Version          : 1.0.0.0
InstanceId       : b55940f2-b3b2-4f99-b895-98aac4752369
UI               : System.Management.Automation.Internal.Host.InternalHostUserInterface
CurrentCulture   : fr-FR
CurrentUICulture : fr-FR
PrivateData      : Microsoft.PowerShell.ConsoleHost+ConsoleColorProxy

My opinion is that PowerShell V2.0 is able to run almost all PowerShell V1.0 scripts. Microsoft add some vars and you can get troubles if you have these vars present in you scripts but it's peanuts.

JP