Windows Update with PowerShell

I’ve had a PowerShell script (rewritten from VBS) for a long time. It works and all, but once in a while when your testing stuff on fresh machines it would drive me nuts I couldn’t get a “status” like when your doing it though GUI.

Doing a progress bar while downloading is/was easy enough, but we all know it’s the installation that takes time, and that gave me a few issues. I finally figured out, I couldn’t re-use the installer, and sometimes it fails if you assign each update without first adding it to an “UpdateColl”. So, here it is (download link)

[CmdletBinding()]
Param
    (
    	[switch]$skipReboot
    )
Begin {
    	$Install = $true;
    	$EulaAccept = $true;

	write-progress -id 1 -Activity "Windows Update" -Status "Initialising"
        $UpdateSession = New-Object -ComObject 'Microsoft.Update.Session'
        $UpdateSession.ClientApplicationID = 'Wingu Update Client'
}
Process {
	write-progress -id 1 -Activity "Windows Update" -Status "Checking for available updates"
	$UpdateSearcher = $UpdateSession.CreateUpdateSearcher()
	$SearchResult = $UpdateSearcher.Search("IsInstalled=0 and Type='Software'") #  and IsHidden=0
	$UpdatesToDownload = New-Object -com Microsoft.Update.UpdateColl
	foreach ($Update in $SearchResult.Updates)
	{
		[bool]$addThisUpdate = $false
		if ($Update.InstallationBehavior.CanRequestUserInput)
		{
			#Write-Verbose "> Skipping: $($Update.Title) because it requires user input"
			[bool]$addThisUpdate = $true
		} else {
			if (!($Update.EulaAccepted)) {
				Write-Verbose "> Note: $($Update.Title) has a license agreement that must be accepted:"
				$Update.AcceptEula() | Out-Null
				[bool]$addThisUpdate = $true
			} else {
				[bool]$addThisUpdate = $true
			}
		}
		if ([bool]$addThisUpdate) {
			Write-Verbose "Adding: $($Update.Title)"
			$UpdatesToDownload.Add($Update) | Out-Null
		}
	}
	if ($UpdatesToDownload.Count -eq 0) {
		Write-Verbose 'All applicable updates were skipped.'
		return $false
	}
	$downloader = $updateSession.CreateUpdateDownloader()
	foreach($update in $UpdatesToDownload) {
		$counter += 1
		write-progress -id 1 -Activity "Updating" -Status "Downloading $counter/$($UpdatesToDownload.count) updates"
		if(!$update.IsDownloaded) {
			write-progress -id 2 -ParentId 1 -Activity "Updating" -Status "Downloading $($update.Title) $([int]($update.MaxDownloadSize / 1MB))MB"
			$updateCollection=New-Object -com Microsoft.Update.UpdateColl
			$updateCollection.Add($Update) | Out-Null
			$downloader.Updates = $updateCollection
			$Result = $downloader.Download()
		} else {
			write-progress -id 2 -ParentId 1 -Activity "Updating" -Status "isready $($update.Title)"
		}
	}


	$needreboot = $false
	$updateSystemInfo = new-object -com Microsoft.Update.SystemInfo
	if($updateSystemInfo.rebootRequired){ $needreboot = $true }
	$counter = 0
	foreach($update in $UpdatesToDownload) {
		$counter += 1
		write-progress -id 1 -Activity "Updating" -Status "Installing $counter/$($UpdatesToDownload.count) updates"
		write-progress -id 2 -ParentId 1 -Activity "Updating" -Status "Installing $($update.Title)"
		$updatesToInstall = New-object -com "Microsoft.Update.UpdateColl"
		$updatesToInstall.Add($update) | out-null
		$installer = $updateSession.CreateUpdateInstaller()
		$updateCollection=New-Object -com Microsoft.Update.UpdateColl
		$updateCollection.Add($Update) | Out-Null
		if($installer.ForceQuiet -eq $false) { $installer.ForceQuiet=$true }
		$installer.Updates = $updateCollection
		$installationResult = $installer.Install()
		if($installationResult.rebootRequired){ $needreboot = $true }
		if($installationResult.HResult -eq 4) {
			#$resultcode= @{0="Not Started"; 1="In Progress"; 2="Succeeded"; 3="Succeeded With Errors"; 4="Failed" ; 5="Aborted" }
			Write-Warning "Failed installting $($update.Title) ResultCode $($installationResult.ResultCode) HResult $($installationResult.HResult)"
		}
		if($installationResult.HResult -eq 5) {
			#$resultcode= @{0="Not Started"; 1="In Progress"; 2="Succeeded"; 3="Succeeded With Errors"; 4="Failed" ; 5="Aborted" }
			Write-Warning "Aborted $($update.Title) ResultCode $($installationResult.ResultCode) HResult $($installationResult.HResult)"
		}
	}

	if(!$needreboot) {
		$arguments = @('/c wuauclt /reportnow')
		Start-Process -FilePath "cmd.exe" -ArgumentList $arguments -Wait
	}
	
	if(!$skipReboot -and $needreboot){
		write-progress -id 2 -ParentId 1 -Activity "Updating" -Status "Rebooting system"
		Write-Warning "Reboot required"
		Restart-Computer -Force
	}
	return $needreboot
}
End {
	write-progress -id 1 -Activity "Updating" -Status "Windows Update Check Complete" -Completed
}