Get-DotNetVersion.ps1

<#	
.SYNOPSIS
Gets the installed .NET versions.

.DESCRIPTION
Gets the versions of all installed Microsoft .NET Framework builds
installed on the local computer. 

.EXAMPLE
.\Get-DotNetVersion

v2.0.50727
v3.0
v3.5
v4.0
4.6.1

.EXAMPLE
.\Get-DotNetVersion -Verbose 

VERBOSE: 4.5+ release is 394254.
v2.0.50727
v3.0
v3.5
v4.0
4.6.2 or later

.NOTES
===========================================================================
 Created with: 	SAPIEN Technologies, Inc., PowerShell Studio 2015 v4.2.99
 Created on:   	2/8/2016 3:41 PM
 Updated on:    8/23/2016
 Created by:   	June Blender
 Organization: 	SAPIEN Technologies, Inc
 Filename:     	Get-DotNetVersion.ps1
===========================================================================
#>
[CmdletBinding()]
param ()

if (!($NDP = Get-ChildItem 'HKLM:\SOFTWARE\Microsoft\NET Framework Setup\NDP' -ErrorAction SilentlyContinue))
{
	throw "Can't find or access the NDP registry key (HKLM\Software\Microsoft\NET Framework Setup\NDP)"
}

$result = ($NDP | Where-Object PSChildName -Like "v*.*").PSChildName
if ($NDP.PSChildName -contains 'v4')
{
	if ($release = (Get-ItemProperty -Name Release -Path 'hklm:\SOFTWARE\Microsoft\NET Framework Setup\NDP\v4\Full\').release)
	{
		Write-Verbose -Message "4.5+ release is $release."
		switch ($release)
		{
			{ $_ -ge 394802 } { $result += "4.6.2 or later"; break }
			{ $_ -ge 394254 } { $result += "4.6.1"; break }
			{ $_ -ge 393295 } { $result += "4.6"; break }
			{ $_ -ge 379893 } { $result += "4.5.2"; break }
			{ $_ -ge 378675 } { $result += "4.5.1"; break; }
			{ $_ -ge 378389 } { $result += "4.5" ; break;}
			default { Write-Information -MessageData "INFORMATION: No 4.5 or later version detected" -InformationAction Continue }
		}		
	}
}

return $result