Manage stale devices

项目
10/30/2024

To complete the device lifecycle, registered devices should be unregistered when they aren't needed anymore. As a result of stolen, lost, broken devices, or OS reinstallations, you typically have some stale devices in your environment. As an IT admin, you probably want a method to remove stale devices, so you can focus your resources on managing devices that actually require management.

To manage stale devices with Microsoft Entra PowerShell, you need:

A Microsoft Entra user account. If you don't have one, you can create an account for free.
A Cloud Device Administrator role (read and modify).
Microsoft Entra PowerShell module installed. Follow the Install the Microsoft Entra PowerShell module guide to install the module.

What is a stale device?

A stale device is a device registered with Microsoft Entra ID that hasn't accessed any cloud apps for a specific timeframe. Stale devices impact your ability to manage and support your devices and users in the tenant because:

Duplicate devices can make it difficult for your helpdesk staff to identify which device is currently active.
An increased number of devices creates unnecessary device writebacks, increasing the time for Microsoft Entra Connect syncs.
As a general hygiene practice and to meet compliance, you might want to have a clean slate of devices.

Stale devices in Microsoft Entra ID can interfere with the general lifecycle policies for devices in your organization.

Detect stale devices

Detecting stale devices requires a timestamp-related property. In Microsoft Entra PowerShell, this property is called ApproximateLastSignInDateTime or activity timestamp. If the delta between now and the value of the activity timestamp exceeds the timeframe you set for active devices, a device is considered stale.

To filter devices by the ApproximateLastSignInDateTime, use:

Connect-Entra -Scopes 'Device.Read.All'  
  
$dt = (Get-Date).AddMonths(-6) # Devices not signed in for the last 6 months  
  
Get-EntraDevice -All |  
Where-Object {  
    $_.ApproximateLastSignInDateTime -le $dt  
} |  
Select-Object -Property AccountEnabled, DeviceId, OperatingSystem, OperatingSystemVersion, DisplayName, TrustType, ApproximateLastSignInDateTime | ft

AccountEnabled DeviceId                             OperatingSystem OperatingSystemVersion DisplayName     TrustType ApproximateLastSignInDateTime
-------------- --------                             --------------- ---------------------- -----------     --------- -----------------------------
         False aaaaaaaa-0000-1111-2222-bbbbbbbbbbbb Windows         10.0.22621.4169        devicesTest2    Entra ID   10/16/2024 4:53:46 PM
          True bbbbbbbb-1111-2222-3333-cccccccccccc Windows         10.0.22631.4169        device1         Workplace 10/15/2024 4:11:33 PM
          True cccccccc-4444-5555-6666-dddddddddddd Windows         10.0.22621.4169        AdminTestEntra  Entra ID   9/13/2024 5:46:08 PM

Clean up stale devices

A typical routine for cleaning up stale devices consists of the following steps:

Connect to Microsoft Entra ID using the Connect-Entra cmdlet.
Get the list of stale devices.
Disable the device using the Set-EntraDevice cmdlet to set -AccountEnabled to False.
Wait for the grace period of the set number of days before deleting the device.
Remove the device using the Remove-EntraDevice cmdlet.

Export list of stale devices

Use the timestamp filter to get all devices that don't have sign-in data in the last six months and store the returned data in a CSV file.

Connect-Entra -Scopes 'Device.Read.All'  
  
$dt = (Get-Date).AddMonths(-6) # Devices not signed in for the last 6 months
  
$staleDevices = Get-EntraDevice -All |  
Where-Object {  
    $_.ApproximateLastSignInDateTime -le $dt  
} |  
Select-Object -Property AccountEnabled, DeviceId, OperatingSystem, OperatingSystemVersion, DisplayName, TrustType, ApproximateLastSignInDateTime  
  
$staleDevices | Export-Csv "$env:UserProfile\Downloads\stale-devices1.csv" -NoTypeInformation

Ensure to replace $env:UserProfile with the path where you want to save the file based on your environment. This example saves the CSV file directly to your Downloads folder.

Warning

Some active devices may have a blank timestamp.

Disable stale devices

Using the previous example for getting the list of stale devices, you can pipe the output to the set command to disable the devices over a certain age.

Connect-Entra -Scopes 'Device.ReadWrite.All'  
  
$dt = (Get-Date).AddMonths(-6) # Devices not signed in for the last 6 months  

Get-EntraDevice -All | 
Where-Object {
    $_.ApproximateLastSignInDateTime -le $dt
} | 
Set-EntraDevice -AccountEnabled $false

Delete stale devices

Caution

The Remove-EntraDevice cmdlet doesn't provide a warning. Running this command will delete devices without prompting. There is no way to recover deleted devices.

Before you delete any devices, back up any BitLocker recovery keys you might need in the future. There's no way to recover BitLocker recovery keys after deleting the associated device.

Building on the disable stale devices example, look for disabled devices, inactive for six months, and pipe the output to Remove-EntraDevice to delete those devices.

Connect-Entra -Scopes 'Device.ReadWrite.All'   
$dt = (Get-Date).AddMonths(-6) # Devices not signed in for the last 6 months  
  
Get-EntraDevice -All |  
Where-Object {  
    ($_.ApproximateLastSignInDateTime -le $dt) -and  
    ($_.AccountEnabled -eq $false)  
} |  
Remove-EntraDevice

What you should know

The following section outlines some common questions and answers about managing stale devices:

Why is the timestamp not updated more frequently?

The timestamp is updated to support device lifecycle scenarios. This attribute isn't an audit. Use the sign-in audit logs for more frequent updates on the device. Some active devices might have a blank timestamp.

What happens when I disable a device?

Any authentication where a device is used to authenticate to Microsoft Entra ID is denied. Common examples are:

Microsoft Entra hybrid joined device - Users might be able to use the device to sign in to their on-premises domain. However, they can't access Microsoft Entra resources such as Microsoft 365.
Microsoft Entra joined device - Users can't use the device to sign in.
Mobile devices - Users can't access Microsoft Entra resources such as Microsoft 365.

Managing devices using Microsoft Entra PowerShell provides a robust and efficient way to ensure your organization's devices are secure and compliant. By following the steps and best practices outlined in this article, you can effectively manage your device environment and stay ahead of potential issues.

Why should I worry about my BitLocker keys?

When configured, BitLocker keys for Windows 10 or newer devices are stored on the device object in Microsoft Entra ID. If you delete a stale device, you also delete the BitLocker keys stored on the device. Confirm that your cleanup policy aligns with the actual lifecycle of your device before deleting a stale device.

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