Automatically remove inactive devices that do not exist in AD

The following script will query Configmgr for inactive devices and automatically remove them if they are no longer in Active Directory. Personally I prefer this simple script over the built in Configmgr maintenance task (Delete Inactive Client Discovery Data) because the task does not check Active Directory and it will remove any inactive device with the criteria that you have configured. By default, this maintenance task will remove any device that has been inactive for 90 days. At least in my environment, if a computer does not exist in Active Directory it should not be in MEMCM so I have the script run on a daily basis as a scheduled task to remove the devices that are not in AD.

Keep in mind to not run this script if you have workgroup computers because they will be deleted since they are not in AD.

Powershell Scripts:

Single Domain Environment:

$InactiveClients = Get-CMDevice | Where-Object { $_.ClientActiveStatus -eq 0 -or $_.ClientActiveStatus -eq $null -and $_.Name -notlike "*Unknown Computer*"}

ForEach($InactiveClient in $InactiveClients) {
    
    Try {

        If(-not(Get-ADComputer -Identity $($InactiveClient.Name))) { }

    }
    Catch {
    
        Write-Host "Removing: $($InactiveClient.Name)"
        Remove-CMDevice -Name $($InactiveClient.Name) -Force
    
    }

}

Multi Domain Environment:

$InactiveClients = Get-CMDevice | Where-Object { $_.ClientActiveStatus -eq 0 -or $_.ClientActiveStatus -eq $null -and $_.Name -notlike "*Unknown Computer*"}

$Domains = (Get-ADForest).Domains

[System.Collections.ArrayList]$Computers = @()


ForEach($InactiveClient in $InactiveClients) {

    ForEach($Domain in $Domains) {

        Try {

             If(-not(Get-ADComputer -Identity $($InactiveClient.Name) -Server $Domain)) { }

 
        }
        Catch {
     
            $Computers += $InactiveClient.Name
     
        }
        

    }
 
}

$ComputersNotInAD = ($Computers | Group-Object | Where-Object { $_.Count -eq $Domains.Count }).Values

Foreach($Computer in $ComputersNotInAD) {

    Write-Host "Removing: $Computer"
    Remove-CMDevice -Name $Computer -Force

}