Anzeigenamen / Vollständigen Name per PowerShell im AD für alle User ändern

Import-Module ActiveDirectory
 
$DomainDN = (Get-ADDomain).DistinguishedName
$OU = 'OU=Benutzer,OU=derTest,' + $DomainDN
 
Get-ADUser -Filter * -SearchBase $OU | ForEach-Object {
    $Vorname =  $_.GivenName
    $Nachname = $_.Surname
    $SamAccountName = $_.samAccountName
    $DistinguishedName = $_.DistinguishedName
    $Anzeigename = $Nachname + ', ' + $Vorname
    Write-Host $Anzeigename
    Set-ADUser $SamAccountName -DisplayName $Anzeigename
    Rename-ADObject -Identity $DistinguishedName -NewName $Anzeigename
}