In System Center Configuration Manager there are 2 Site Maintenance tasks that help take care of stale or obsolete client records: Delete Aged Discovery Data and Delete Inactive Client Discovery Data. However in some cases some records can remain in SCCM and are not removed by these tasks, for example, when a system is no longer active but the computer account has not been deleted or disabled in Active Directory.  AD System Discovery will continue to pick this system up and create a record for it, so maintenance of AD computer accounts is essential for a healthy ConfigMgr environment.

As long as a client is disabled or deleted from Active Directory and does not get picked up by any of the discovery methods, it will eventually get deleted from SCCM according to the schedule defined in these maintenance tasks.

For computer accounts that are disabled however, you might not want to wait for the maintenance tasks to remove them since you know they are no longer active and can safely be deleted from the SCCM database.  Removing them sooner can improve compliance figures for deployment reporting, for example. For this scenario, I prepared a PowerShell script that can run as a scheduled task and remove any system that is marked as inactive – or does not have the SCCM client installed – and is also disabled or not present in active directory.

I’ll run through the script quickly here to explain what it does.

First we define some variables to be used in the script, such as the site code, the site server, and the email information (the script will email the SCCM admin with the list of systems it deletes):

$SiteCode = "ABC"
$SiteServer = "SCCMSERVER-01"
$EmailRecipient = "joe.blow@contoso.com"
$EmailSender = "PowerShell@contoso.com"
$SMTPServer = "SMTPServer.contoso.com"

Then we create a list of discovered systems in SCCM that are either inactive (determined by client health data) or have no SCCM client installed, using WMI on the site server:

try
{
    $DevicesToCheck = Get-WmiObject -ComputerName $SiteServer -Namespace root\SMS\Site_$SiteCode -Query "SELECT SMS_R_System.Name FROM SMS_R_System left join SMS_G_System_CH_ClientSummary on SMS_G_System_CH_ClientSummary.ResourceID = SMS_R_System.ResourceID where (SMS_G_System_CH_ClientSummary.ClientActiveStatus = 0 or SMS_R_System.Active = 0 or SMS_R_System.Active is null)" -ErrorAction Stop |
        Select -ExpandProperty Name |
        Sort
}
Catch
{
    $_
}

Next we check active directory for each system to find the status of the computer account and filter those that are either disabled or not present in AD using a custom function. Note that this function uses .Net to search AD so it is not dependent on having the RSAT tools installed.

$NotEnabledDevices = ($DevicesToCheck | foreach {
    Get-IsComputerAccountDisabled  -Computername $_
}) | where {$_.IsDisabled -ne $False}

Then we will attempt to remove each resulting system from SCCM using another custom function.  This function uses WMI rather than the ConfigMgr PS cmdlets, again to remove the dependency.

$DeletedRecords = New-Object System.Collections.ArrayList
$Output = $NotEnabledDevices| foreach {
    Remove-CMRecord -Computername $_.ComputerName -DeviceStatus $_.IsDisabled -SiteCode $SiteCode -SiteServer $SiteServer
    }
$DeletedRecords.AddRange(@($Output))

Finally we send an HTML formatted email to the SCCM administrator with the list of systems that were deleted from SCCM:

If ($DeletedRecords.Count -ne 0)
{
    $Body = $DeletedRecords | ConvertTo-Html -Head $style -Body "
<h2>The following computer accounts are either disabled or not present in active directory and have been deleted from SCCM</h2>
" | Out-String
    Send-MailMessage -To $EmailRecipient -From $EmailSender  -Subject "Disabled Computer Accounts Deleted from SCCM ($(Get-Date -format 'yyyy-MMM-dd'))" -SmtpServer $SMTPServer -Body $body -BodyAsHtml
}

To verify in SCCM the systems that were deleted you can view the All Audit Status Messages from a Specific Site status message query.

IMPORTANT: As this script deletes records from the SCCM database, please be sure to understand what it does and to test it first before using it in any production environment!

Here is the full script:

$SiteCode = "ABC"
$SiteServer = "SCCMSERVER-01"
$EmailRecipient = "joe.blow@contoso.com"
$EmailSender = "PowerShell@contoso.com"
$SMTPServer = "SMTPServer.contoso.com"

#region Functions

# Function to check with the computer account is disabled
function Get-IsComputerAccountDisabled
{
  param($Computername)

  $root = [ADSI]''
  $searcher = New-Object -TypeName System.DirectoryServices.DirectorySearcher -ArgumentList ($root)
  $searcher.filter = "(&(objectClass=Computer)(Name=$Computername))"
  $Result = $searcher.findall()
  If ($Result.Count -ne 0)
  {
    $Result | ForEach-Object {
        $Computer = $_.GetDirectoryEntry()
        [pscustomobject]@{
            ComputerName = $Computername
            IsDisabled = $Computer.PsBase.InvokeGet("AccountDisabled")
        }
    }
  }
  Else
  {
      [pscustomobject]@{
      ComputerName = $Computername
      IsDisabled = "Not found in AD"
      }
  }
}

# Function to remove the device record from SCCM via WMI
function Remove-CMRecord
{
    [CmdletBinding()]

    Param
    (
        [Parameter(Mandatory = $True, ValueFromPipelineByPropertyName = $True)] [string] $Computername,
        [Parameter(Mandatory = $True)] [string] $SiteCode,
        [Parameter(Mandatory = $True)] [string] $SiteServer,
        [Parameter(Mandatory = $True)] [string] $DeviceStatus

    )

    Begin
    {
        $ErrorAction = 'Stop'
    }

    Process
    {

        # Check if the system exists in SCCM
        Try
        {
            $Computer = [wmi] (Get-WmiObject -ComputerName $SiteServer -Namespace "root\sms\site_$SiteCode" -Class sms_r_system -Filter "Name = `'$Computername`'" -ErrorAction Stop).__PATH
        }
        Catch
        {
            $Result = $_
            Continue
        }

        # Delete it
        Try
        {
            $Computer.psbase.delete()
        }
        Catch
        {
            $Result = $_
            Continue
        }

        # Check that the delete worked
        Try
        {
            $Computer = [wmi] (Get-WmiObject -ComputerName $SiteServer -Namespace "root\sms\site_$SiteCode" -Class sms_r_system -Filter "Name = `'$Computername`'" -ErrorAction Stop).__PATH
        }
        Catch
        {

        }

        # Report result
        If ($Computer.PSComputerName)
        {
            $Result = "Tried to delete but record still exists"
        }
        Else
        {
            $Result = "Successfully deleted"
        }
    }

    End
    {
        [pscustomobject]@{
        DeviceName = $Computername
        IsDisabled = $DeviceStatus
        Result = $Result
        }
    }
}

#endregion

# Let's get the list of inactive systems, or systems with no SCCM client, from WMI
try
{
    $DevicesToCheck = Get-WmiObject -ComputerName $SiteServer -Namespace root\SMS\Site_$SiteCode -Query "SELECT SMS_R_System.Name FROM SMS_R_System left join SMS_G_System_CH_ClientSummary on SMS_G_System_CH_ClientSummary.ResourceID = SMS_R_System.ResourceID where (SMS_G_System_CH_ClientSummary.ClientActiveStatus = 0 or SMS_R_System.Active = 0 or SMS_R_System.Active is null)" -ErrorAction Stop |
        Select -ExpandProperty Name |
        Sort
}
Catch
{
    $_
}

# Now let's filter those systems whose AD account is disabled or not present
$NotEnabledDevices = ($DevicesToCheck | foreach {
    Get-IsComputerAccountDisabled  -Computername $_
}) | where {$_.IsDisabled -ne $False}

# Then we will delete each record from SCCM using WMI
$DeletedRecords = New-Object System.Collections.ArrayList
$Output = $NotEnabledDevices| foreach {
    Remove-CMRecord -Computername $_.ComputerName -DeviceStatus $_.IsDisabled -SiteCode $SiteCode -SiteServer $SiteServer
    }
$DeletedRecords.AddRange(@($Output))

# Finally we will send the list of affected systems to the administrator
$style = @"
<style>
body {
    color:#333333;
    font-family: ""Trebuchet MS"", Arial, Helvetica, sans-serif;}
}
h1 {
    text-align:center;
}
table {
    border-collapse: collapse;
    font-family: ""Trebuchet MS"", Arial, Helvetica, sans-serif;
}
th {
    font-size: 10pt;
    text-align: left;
    padding-top: 5px;
    padding-bottom: 4px;
    background-color: #1FE093;
    color: #ffffff;
}
td {
    font-size: 8pt;
    border: 1px solid #1FE093;
    padding: 3px 7px 2px 7px;
}
</style>

"@
If ($DeletedRecords.Count -ne 0)
{
    $Body = $DeletedRecords | ConvertTo-Html -Head $style -Body "
<h2>The following systems are either disabled or not present in active directory and have been deleted from SCCM</h2>
" | Out-String
    Send-MailMessage -To $EmailRecipient -From $EmailSender  -Subject "Disabled Computer Accounts Deleted from SCCM ($(Get-Date -format 'yyyy-MMM-dd'))" -SmtpServer $SMTPServer -Body $body -BodyAsHtml
}