Test-PendingReboot.ps1

 
 # PowerShell
 function Test-PendingReboot
 {
   $svc  = "HKLM:\Software\Microsoft\Windows\CurrentVersion\" `
         + "Component Based Servicing\RebootPending";
 
   $wupd = "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\" `
         + "WindowsUpdate\Auto Update\RebootRequired"
 
   $file = "HKLM:\SYSTEM\CurrentControlSet\Control\Session Manager";
 
   $reasons = 0;
 
   if (Get-ChildItem $svc -EA Ignore) 
   { $reasons += 1; }
 
   if (Get-Item $wupd -EA Ignore) 
   { $reasons += 2; }
 
   if (Get-ItemProperty $file -Name PendingFileRenameOperations -EA Ignore) 
   { $reasons += 4; }
 
   try 
   { 
     $util = [wmiclass]"\\.\root\ccm\clientsdk:CCM_ClientUtilities"
     $status = $util.DetermineIfRebootPending()
     if(($status -ne $null) -and $status.RebootPending)
     {
       $reasons += 8;
     }
   }catch{}
 
   return $reasons;
 }
 
 Test-PendingReboot;