How do I get PowerShell 4 cmdlets such as Test-NetConnection to work on Windows 7?

The situation. On a Windows 7 SP1 machine, I have updated with Windows6.1-KB2819745-x64-MultiPkg.msu. Furthermore, in PowerShell $PSVersionTable now reports ‘PSVersion 4.0’.

At present, my conclusion is that many PowerShell 4 cmdlets such Test-NetConnection, will only work on Windows 8.1. However, I was wondering if there was a work-around whereby I could import PowerShell 4 modules on my Windows 7 machine.

Solution

You cannot. They rely on the underlying features of the newer OS (8.0 or 8.1) and cannot be ported back to Windows 7 . The alternative is to write your own functions / modules to replicate the new cmdlets using .NET framework methods.

For instance, the Get-FileHash cmdlet is a one-liner in PowerShell 4.0, but to replicate in 2.0 we have to use .NET.

PowerShell v4

Get-FileHash -Algorithm SHA1 "C:\Windows\explorer.exe"

PowerShell v2

$SHA1 = new-object -TypeName System.Security.Cryptography.SHA1CryptoServiceProvider
$file = [System.IO.File]::Open("C:\Windows\explorer.exe",[System.IO.Filemode]::Open, [System.IO.FileAccess]::Read)
[System.BitConverter]::ToString($SHA1.ComputeHash($file)) -replace "-",""
$file.Close()