scripts/MDT-WinUpdate.ps1

# Run Windows Update
# iRaven
# 2025-07-30

<#
.SYNOPSIS
Updates windows with PSWindowsUpdate
.PARAMETER MDT
Set this if being used with MDT so logs get put in the right place 
.PARAMETER Reboot
Allow system reboots
#>

## Initial Tasks
param(
	[switch] $MDT,
    [switch] $Reboot
)

$ErrorActionPreference = "Continue"
$PSModulePathCU = $env:PSModulePath.split(';')[0] # CurrentUser PSModule path
$PSModulePathAU = $env:PSModulePath.split(';')[1] # All Users PSModule path
if ($MDT){
	$MDTPath = $Global:TSEnv.Value("DeployRoot")	
}

$WUServer = (Get-ItemProperty HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate).WUServer

## Functions

Function SetWUServer {
	if (!(test-path HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate)){
		New-Item -Path "HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate"
	}
	New-ItemProperty -Path "HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate" -Name WUServer -Value "http://fluttershy.technolog.net:8530"
	New-ItemProperty -Path "HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate" -Name WUStatusServer -Value "http://fluttershy.technolog.net:8530"
	if (!(test-path HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate\AU)){
		New-Item -Path "HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate\AU"
	}
	New-ItemProperty -Path "HKLM:\Software\Policies\Microsoft\Windows\WindowsUpdate" -Name UseWUServer -Value 0
	
}
Function ImportPSWindowsUpdate {
	Write-Host -ForegroundColor Yellow "Importing PS Windows Update module..."
	# Write-LogEntry -Value "Importing PS Windows Update Module..." -Severity 1 -Component "ImportPSWindowsUpdate" -FileName $ScriptLog
	try {
		if (!(Test-Path -Path $PSModulePathAU\PSWindowsUpdate -PathType Container)){
			# Get from PSGallery/NuGet
			Write-Host -ForegroundColor Yellow "Installing PSWindowsUpdate from PSGallery"
			if (!(Get-PackageProvider -ListAvailable -Name 'NuGet' -ErrorAction Ignore)) {
				Write-Host -ForegroundColor Yellow 'Installing NuGet package provider...'
				Install-PackageProvider -Name 'NuGet' -Force
				Install-Module -Name PSWindowsUpdate -Scope AllUsers -Force
			} else {	
				Install-Module -Name PSWindowsUpdate -Scope AllUsers -Force
			}
		}
		Import-Module PSWindowsUpdate -Force
		Write-Host -ForegroundColor Green "PSWindowsUpdate module imported!"
		Write-LogEntry -Value "PSWindowsUpdate module imported!" -Severity 1 -Component "ImportPSWindowsUpdate" -FileName $ScriptLog
		return $true
	} catch {
		Write-LogEntry -Value "Failed to import PSWindowsUpdate!" -Severity 3 -Component "ImportPSWindowsUpdate" -FileName $ScriptLog
		Write-Host -ForegroundColor Red "Failed to import PSWindowsUpdate!"
		return $false
	}
}

Function RunWinUpdate { # Run Windows Updates
	if(ImportPSWindowsUpdate){
		try {
			Write-LogEntry -Value "Installing all available Windows Updates..." -Severity 1 -Component "RunWinUpdate" -FileName $ScriptLog
			Write-Host -ForegroundColor Yellow "Installing all available Windows Updates..."
			if (($null -eq $WUServer) -and !($Reboot)){
				Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -IgnoreReboot
				#Requires -RunAsAdministrator
			} elseif (($null -eq $WUServer) -and $Reboot){
				Install-WindowsUpdate -MicrosoftUpdate -AcceptAll -AutoReboot
				#Requires -RunAsAdministrator
			} elseif ($WUServer -and $Reboot) {
				Install-WindowsUpdate -AcceptAll -AutoReboot
				#Requires -RunAsAdministrator
			} else {
				Install-WindowsUpdate -AcceptAll -IgnoreReboot
				#Requires -RunAsAdministrator
			}
			return $true
		} catch {
			Write-Host -ForegroundColor Red "Failed installing all available Windows updates!"
			Write-LogEntry -Value "Failed installing all available Windows updates!" -Severity 3 -Component "RunWinUpdate" -FileName $ScriptLog
		}
	} else {
		Write-LogEntry -Value "Failed to update Windows due to failed import of PSWindowsUpdate PS module." -Severity 3 -Component "RunWinUpdate" -FileName $ScriptLog
		return $false
	}
}

Function Write-LogEntry
{
    #Write data to a CMTrace compatible log file. (Credit to SCConfigMgr - https://www.scconfigmgr.com/)

	param(
		[parameter(Mandatory = $true, HelpMessage = "Value added to the log file.")]
		[ValidateNotNullOrEmpty()]
		[string]$Value,
		[parameter(Mandatory = $true, HelpMessage = "Severity for the log entry. 1 for Informational, 2 for Warning and 3 for Error.")]
		[ValidateNotNullOrEmpty()]
		[ValidateSet("1", "2", "3")]
		[string]$Severity,
		[parameter(Mandatory = $true, HelpMessage = "Component of the log file.")]
		[ValidateNotNullOrEmpty()]
		[string]$Component,
		[parameter(Mandatory = $false, HelpMessage = "Name of the log file that the entry will written to.")]
		[ValidateNotNullOrEmpty()]
		[string]$FileName
	)
    #Determine log file location
    $LogFilePath = $FileName
    #Construct time stamp for log entry
    if(-not(Test-Path -Path 'variable:global:TimezoneBias'))
    {
        [string]$global:TimezoneBias = [System.TimeZoneInfo]::Local.GetUtcOffset((Get-Date)).TotalMinutes
        if($TimezoneBias -match "^-")
        {
            $TimezoneBias = $TimezoneBias.Replace('-', '+')
        }
        else
        {
            $TimezoneBias = '-' + $TimezoneBias
        }
    }
    $Time = -join @((Get-Date -Format "HH:mm:ss.fff"), $TimezoneBias)
    #Construct date for log entry
    $Date = (Get-Date -Format "MM-dd-yyyy")
    #Construct context for log entry
    $Context = $([System.Security.Principal.WindowsIdentity]::GetCurrent().Name)
    #Construct final log entry
    $LogText = "<![LOG[$($Value)]LOG]!><time=""$($Time)"" date=""$($Date)"" component=""$($Component)"" context=""$($Context)"" type=""$($Severity)"" thread=""$($PID)"" file="""">"
    #Add value to log file
    try
    {
        Out-File -InputObject $LogText -Append -NoClobber -Encoding Default -FilePath $LogFilePath -ErrorAction Stop
    }
    catch [System.Exception]
    {
        Write-Warning -Message "Unable to append log entry to $FileName file. Error message at line $($_.InvocationInfo.ScriptLineNumber): $($_.Exception.Message)"
    }
}


# Main Program
if ($MDT){
	if ($null -eq $WUServer) {
		SetWUServer
	}
	$ScriptLog = "$MDTPath\_Logs\$env:ComputerName-WindowsUpdate.log"	
} else {
	$ScriptLog = "$env:SystemDrive\irnh\PSWindowsUpdate.log"
}
RunWinUpdate