Report Entra registered devices

Connect-MgGraph -Scopes User.Read.All, Directory.Read.All -NoWelcome

Connect-MgGraph -Scope User.Read.All, Directory.Read.All
 
Write-Host "Finding registered devices"
[array]$Devices = Get-MgDevice -All -PageSize 999
If (!($Devices)) {
  Write-Host "No registered devices found - exiting" ; break
}
 
Write-Host ("Processing details for {0} devices" -f $Devices.count)
$Report = [System.Collections.Generic.List[Object]]::new()
$i = 0
ForEach ($Device in $Devices) {
  $i++
  Write-Host ("Reporting device {0} ({1}/{2})" -f $Device.DisplayName, $i, $Devices.count)
  $DeviceOwner = $Null
  Try {
    [array]$OwnerIds = Get-MgDeviceRegisteredOwner -DeviceId $Device.Id
    $DeviceOwner = Get-MgUser -UserId $OwnerIds[0].Id `
     -Property Id, displayName, Department, OfficeLocation, City, Country, UserPrincipalName -ErrorAction Stop
    }
  Catch {
    Write-Host ("Error fetching owners for {0}" -f $Device.DisplayName)
  }
 
  $ReportLine = [PSCustomObject][Ordered]@{
   Device              = $Device.DisplayName
   Id                  = $Device.Id
  "Device last signed in" = $Device.ApproximateLastSignInDateTime
  "Days since sign in" = (New-TimeSpan($Device.ApproximateLastSignInDateTime)).Days
   Owner               = $DeviceOwner.DisplayName
   OwnerUPN            = $DeviceOwner.UserPrincipalName
   Department          = $DeviceOwner.Department
   Office              = $DeviceOwner.OfficeLocation
   City                = $DeviceOwner.City
   Country             = $DeviceOwner.Country
   "Operating System"  = $Device.OperatingSystem
   "O/S Version"       = $Device.OperatingSystemVersion
   Registered          = $Device.RegistrationDateTime
   "Account Enabled"   = $Device.AccountEnabled
   DeviceId            = $Device.DeviceId
   TrustType           = $Device.TrustType
  }
  $Report.Add($ReportLine)
 
} #End Foreach Device
 
# Sort in order of last signed in date
$Report = $Report | Sort-Object {$_.LastSignIn -as [datetime]} -Descending
$Report | Out-GridView
 
[array]$OldDevices = $Report | Where-Object {$_.'Days Since sign in' -ge 365}
Write-Host ("There are {0} devices that have not signed in for over a year" -f $OldDevices.Count)
$OldDevices | Format-Table Device, 'Device last signed in', 'Days since sign in', Owner, OwnerUPN, Department -AutoSize