How can I run PowerShell with the .NET 4 runtime?

Question

I am updating a PowerShell script that manages some .NET assemblies. The script was written for assemblies built against .NET 2 (the same version of the framework that PowerShell runs with), but now needs to work with .NET 4 assemblies as well as .NET 2 assemblies.

Since .NET 4 supports running applications built against older versions of the framework, it seems like the simplest solution is to launch PowerShell with the .NET 4 runtime when I need to run it against .NET 4 assemblies.

How can I run PowerShell with the .NET 4 runtime?

Answer 1

The best solution I have found is in the blog post Using Newer Version(s) of .NET with PowerShell. This allows powershell.exe to run with .NET 4 assemblies.

Simply modify (or create) $pshome\powershell.exe.config so that it contains the following:

<?xml version="1.0"?> 
<configuration> 
    <startup useLegacyV2RuntimeActivationPolicy="true"> 
        <supportedRuntime version="v4.0.30319"/> 
        <supportedRuntime version="v2.0.50727"/> 
    </startup> 
</configuration> 

Additional, quick setup notes:

Locations and files are somewhat platform dependent; however will give you an inline gist of how to make the solution work for you.

• You can find PowerShell's location on your computer by executing cd $pshome in the Powershell window (doesn't work from DOS prompt).
  • Path will be something like (example) C:\Windows\System32\WindowsPowerShell\v1.0\
• The filename to put configuration in is: powershell.exe.config if your PowerShell.exe is being executed (create the config file if need be).
  • If PowerShellISE.Exe is running then you need to create its companion config file as PowerShellISE.Exe.config