Get-GpoHistory.ps1

<#
.Synopsis
   Get Group Policy Object Id that have been applied in the past
.DESCRIPTION
   Get Group Policy Object Id that have been applied in the past
.EXAMPLE
   Get-GpoHistory -Scope Machine
#>
function Get-GpoHistory
{
    [CmdletBinding()]
    Param
    (
        # Hilfebeschreibung zu Param1
        [Parameter(Mandatory=$false)]
        [ValidateSet("Machine")]
        [String]$Scope
    )

    Process {
        $gpoObjHist = @()
        $key = 'HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Group Policy\History'
        $gpoHistArr = Get-ChildItem -Path $key
        $gpoHistArr | ForEach-Object {Get-ChildItem $_.PSPath} | ForEach-Object {$gpoObjHist += (Get-ItemPropertyValue -Path $_.PSPath -Name DisplayName)}
        return $gpoObjHist
    }
}