Install-WindowsUpdates.ps1

Param(
    [switch] $RebootAfterInstall
)

# Default Variables
# -----------------
$PSDefaultParameterValues = @{
    "Out-File:Encoding" = 'utf8';
};

$sVar = @{
    ClientApplicationID = 'UpdateOrchestrator';
};
$ServerSelection = '1';
$ServiceID = @(
    '00000000-0000-0000-0000-000000000000',
    '3da21691-e39d-4da6-8a4b-b43877bcb1b7',
    '9482f4b4-e343-43b6-b170-9a65bc822c77',
    '7971f918-a847-4430-9279-4a52d1efe18d'
);
$WUAServiceSelected = @(
    'Auto',
    'WSUS',
    'Windows Update',
    'Microsoft Update'
);

$NumUpdatesDownloaded = 0;
$NumUpdatesFound = 0;
$NumUpdatesInstalled = 0;
$RebootRequired = $False;
$RebootPending = (New-Object -ComObject 'Microsoft.Update.SystemInfo').RebootRequired;

# Start logging
# -------------
$timestamp = Get-Date -UFormat '+%Y%m%d%H%M%S';
$logfile = "$($env:SystemRoot)\Temp\PoSh-WindowsUpdates_$($timestamp).log";
Get-Date | Out-File -LiteralPath $logfile -Force;

<#-------------------------------------------------------------------------------------------------------------------

## WUA.ServiceManager
$UpdateServiceManager = New-Object -ComObject 'Microsoft.Update.ServiceManager';
$UpdateServiceManager.ClientApplicationID = $sVar['ClientApplicationID'];
$UpdateServiceManager.SetOption('AllowWarningUI', $false);
$smMicrosoftUpdate = '';
$smMicrosoftUpdate = ( $UpdateServiceManager.Services | Where-Object { $_.ServiceID -eq $ServiceID[3] } );
if ( [object]::Equals($null, $smMicrosoftUpdate) )
    {
        $UpdateServiceManager.AddService2($ServiceID[3], 7, '') | Out-Null;
        $UpdateServiceManager.RegisterServiceWithAU($ServiceID[3]) | Out-Null;
    }
elseif ( $smMicrosoftUpdate.IsRegisteredWithAU -ne $True )
    {
        $UpdateServiceManager.RegisterServiceWithAU($ServiceID[3]) | Out-Null;
    };

-------------------------------------------------------------------------------------------------------------------#>

## WUA.Session
$UpdateSession = New-Object -ComObject 'Microsoft.Update.Session';
$UpdateSession.ClientApplicationID = $sVar['ClientApplicationID'];

# Search for Updates
$UpdateSearcher = $UpdateSession.CreateUpdateSearcher();
$UpdateSearcher.ClientApplicationID = $sVar['ClientApplicationID'];
$UpdateSearcher.ServerSelection = $ServerSelection;
$UpdateSearcher.ServiceID = $ServiceID[$UpdateSearcher.ServerSelection];

$SearchCriteria  = "IsInstalled=0 and IsHidden=0 and AutoSelectOnWebSites=1 and Type='Software' or ";
$SearchCriteria += "IsInstalled=0 and IsHidden=0 and IsAssigned=1 and Type='Software' or ";
$SearchCriteria += "IsInstalled=0 and IsHidden=0 and DeploymentAction='Installation' or ";
$SearchCriteria += "IsInstalled=0 and IsHidden=0 and DeploymentAction='OptionalInstallation' or ";
$SearchCriteria += "IsInstalled=1 and IsHidden=0 and DeploymentAction='Installation' and RebootRequired=1";

Try {
    $UpdatesToDownload = $UpdateSearcher.Search($SearchCriteria);
}
Catch {
    $_ | Out-File -LiteralPath $logfile -Append;
    $UpdateSearcher.ServerSelection = '0';
    $UpdateSearcher.ServiceID = $ServiceID[$UpdateSearcher.ServerSelection];
    $SearchCriteria  = "IsInstalled=0 and IsHidden=0 and AutoSelectOnWebSites=1 and Type='Software' or ";
    $SearchCriteria += "IsInstalled=0 and IsHidden=0 and IsAssigned=1 and Type='Software'";
    $UpdatesToDownload = $UpdateSearcher.Search($SearchCriteria);
};

$NumUpdatesFound = ($UpdatesToDownload.Updates | Measure-Object).Count;
If ( $NumUpdatesFound -gt 0 ){
	$UpdatesToDownload = $UpdatesToDownload.Updates;
	$UpdatesToDownload | ForEach-Object { "[ Found ] $($_.Title)" | Out-File -LiteralPath $logfile -Append; };
	$UpdatesToInstall = New-Object -ComObject 'Microsoft.Update.UpdateColl';

	# Download Updates
	foreach ( $Update in $UpdatesToDownload )
	{
		If ( $Update.InstallationBehavior.CanRequestUserInput ) { continue };
		$Update.AcceptEula();
		$objCollectionTmp = New-Object -ComObject 'Microsoft.Update.UpdateColl';
		$objCollectionTmp.Add($Update) | Out-Null;

		$Downloader = $UpdateSession.CreateUpdateDownloader();
		$Downloader.Updates = $objCollectionTmp;
		Try {
			"[ Download ] $($Update.Title) -> " | Out-File -LiteralPath $logfile -Append -NoNewline;
			$DownloadResult = $Downloader.Download();
		}
		Catch {
			"ERROR." | Out-File -LiteralPath $logfile -Append;
			continue
		};
	 
		If ( ($DownloadResult.ResultCode -eq 2) -or ($Update.IsDownloaded) ) {
			"success." | Out-File -LiteralPath $logfile -Append;
			$UpdatesToInstall.Add($Update) | Out-Null;
			$NumUpdatesDownloaded++;
		}
		Else {
			"failure." | Out-File -LiteralPath $logfile -Append;
		};
	};

	# Install Updates
	foreach ( $Update in $UpdatesToInstall )
	{
		$objCollectionTmp = New-Object -ComObject 'Microsoft.Update.UpdateColl';
		$objCollectionTmp.Add($Update) | Out-Null;
		$Installer = $UpdateSession.CreateUpdateInstaller();
		$Installer.Updates = $objCollectionTmp;
	 
		Try {
			"[ Install ] $($Update.Title) -> " | Out-File -LiteralPath $logfile -Append -NoNewline;
			$InstallResult = $Installer.Install();
		}
		Catch {
			"failure." | Out-File -LiteralPath $logfile -Append;
			continue
		};
	 
		If ( $InstallResult.ResultCode -eq 2 ){
			"success." | Out-File -LiteralPath $logfile -Append;
			$NumUpdatesInstalled++;
		}
		Else {
			"failure." | Out-File -LiteralPath $logfile -Append;
		};
	 
		If ( $RebootRequired -ne $True ){
			$RebootRequired = $InstallResult.RebootRequired;
		};
	};
};

"Update Service selected: $($WUAServiceSelected[$($UpdateSearcher.ServerSelection)])" | Out-File -LiteralPath $logfile -Append;
"Updates found: $NumUpdatesFound" | Out-File -LiteralPath $logfile -Append;
"Updates downloaded: $NumUpdatesDownloaded" | Out-File -LiteralPath $logfile -Append;
"Updates installed: $NumUpdatesInstalled" | Out-File -LiteralPath $logfile -Append;
"Reboot pending: $RebootPending" | Out-File -LiteralPath $logfile -Append;
"Reboot required: $RebootRequired" | Out-File -LiteralPath $logfile -Append;

Get-Date | Out-File -LiteralPath $logfile -Append;

if ($RebootAfterInstall -and ($RebootRequired -or $RebootPending)) { Restart-Computer -Force }