Update Check-WSUS-AdminAssembly.ps1

Signed-off-by: LUIZ HAMILTON ROBERTO DA SILVA <[email protected]>

Author: brazilianscriptguy

SysAdmin-Tools/WSUS-Management-Tools/Check-WSUS-AdminAssembly.ps1

@@ -1,20 +1,23 @@
 <#
 .SYNOPSIS
-    Validates the presence of Microsoft.UpdateServices.Administration.dll in the Global Assembly Cache (GAC).
+    Validates and loads Microsoft.UpdateServices.Administration.dll (WSUS Admin API).
 
 .DESCRIPTION
-    This script checks whether the WSUS Administration Console assembly is loaded in the current PowerShell session.
-    If not, it attempts to load it from the Global Assembly Cache (GAC). If that fails, it attempts to load it directly
-    from a known file path. The script also displays GUI message boxes to assist the user with guidance and diagnostics.
+    - Prefers Import-Module UpdateServices (works when WSUS Management Tools are installed).
+    - If the module isn't available, attempts to load the WSUS Admin assembly from the GAC.
+    - Searches common GAC roots on modern and legacy systems.
+    - Falls back to a known explicit path if provided.
+    - Uses small WinForms message boxes for guidance/diagnostics.
+    - Hides the console window (comment out [Window]::Hide() while debugging).
 
 .AUTHOR
     Luiz Hamilton Silva - @brazilianscriptguy
 
 .VERSION
-    Last Updated: July 11, 2025
+    Last Updated: Sep 15, 2025
 #>
 
-# Hide Console Window
+# ---------------- Console (hidden) ----------------
 Add-Type @"
 using System;
 using System.Runtime.InteropServices;
@@ -24,76 +27,135 @@ public class Window {
     [DllImport("user32.dll", SetLastError = true)]
     [return: MarshalAs(UnmanagedType.Bool)]
     static extern bool ShowWindow(IntPtr hWnd, int nCmdShow);
-    public static void Hide() {
-        var handle = GetConsoleWindow();
-        ShowWindow(handle, 0);
-    }
+    public static void Hide() { var handle = GetConsoleWindow(); ShowWindow(handle, 0); }
 }
 "@
-[Window]::Hide()
+[Window]::Hide()  # <-- comment this line while debugging to keep the console visible
 
-# Load required assemblies
+# ---------------- UI + utils ----------------
 Add-Type -AssemblyName System.Windows.Forms
 [System.Windows.Forms.Application]::EnableVisualStyles()
 
-# Logging function 
 function Write-Log {
-    param (
-        [string]$Message,
-        [ValidateSet("INFO", "WARNING", "ERROR")][string]$Level
+    param(
+        [Parameter(Mandatory)][string]$Message,
+        [ValidateSet("INFO","WARNING","ERROR")] [string]$Level = "INFO"
     )
-
-    $timestamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
-    $formatted = "[$timestamp] [$Level] $Message"
-    Write-Output $formatted
+    $stamp = Get-Date -Format "yyyy-MM-dd HH:mm:ss"
+    Write-Output "[$stamp] [$Level] $Message"
 }
 
 function Show-MessageBox {
-    param (
-        [string]$Message,
+    param(
+        [Parameter(Mandatory)][string]$Message,
         [string]$Title = "WSUS Administration Assembly Check",
         [System.Windows.Forms.MessageBoxButtons]$Buttons = [System.Windows.Forms.MessageBoxButtons]::OK,
         [System.Windows.Forms.MessageBoxIcon]$Icon = [System.Windows.Forms.MessageBoxIcon]::Information
     )
     [System.Windows.Forms.MessageBox]::Show($Message, $Title, $Buttons, $Icon) | Out-Null
 }
 
-# Define the expected path to the WSUS Administration assembly in the GAC
-$wsusAssemblyPath = "C:\Windows\Microsoft.Net\assembly\GAC_MSIL\Microsoft.UpdateServices.Administration\v4.0_4.0.0.0__31bf3856ad364e35\Microsoft.UpdateServices.Administration.dll"
+# If you want to pin a known path (kept from your original script).
+$ExplicitAssemblyPath = "C:\Windows\Microsoft.Net\assembly\GAC_MSIL\Microsoft.UpdateServices.Administration\v4.0_4.0.0.0__31bf3856ad364e35\Microsoft.UpdateServices.Administration.dll"
+
+# Common GAC roots on modern/legacy systems
+# Common GAC roots on modern/legacy systems
+$GacRoots = @(
+    (Join-Path $env:WINDIR 'Microsoft.NET\assembly\GAC_MSIL')  # .NET 4+ (Win10/2016+)
+    (Join-Path $env:WINDIR 'assembly\GAC_MSIL')                 # legacy view
+)
+
+# ---------------- Helper: Is Assembly Loaded? ----------------
+function Test-AssemblyLoaded {
+    [OutputType([bool])]
+    param([string]$PartialName = "Microsoft.UpdateServices.Administration")
+    return [AppDomain]::CurrentDomain.GetAssemblies().FullName -match [regex]::Escape($PartialName)
+}
+
+# ---------------- Try 1: Import-Module UpdateServices ----------------
+try {
+    if ($PSVersionTable.PSEdition -eq 'Core') {
+        # PowerShell 7+: use Windows PowerShell compatibility shim if available
+        Import-Module -Name UpdateServices -UseWindowsPowerShell -ErrorAction Stop
+    } else {
+        Import-Module -Name UpdateServices -ErrorAction Stop
+    }
+
+    if (Test-AssemblyLoaded) {
+        Write-Log "WSUS Administration assembly available via UpdateServices module." -Level INFO
+        Show-MessageBox -Message "WSUS Administration assembly is available (loaded with UpdateServices module)."
+        return
+    }
+} catch {
+    Write-Log "UpdateServices module not available or failed to load: $($_.Exception.Message)" -Level WARNING
+}
 
-# Attempt to load the assembly by partial name (GAC)
+# ---------------- Try 2: Load from GAC (by partial name) ----------------
 try {
-    $assembly = [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.UpdateServices.Administration")
-    if ($assembly) {
-        Write-Log "WSUS Administration assembly loaded successfully from GAC." -Level INFO
-        Show-MessageBox -Message "WSUS Administration assembly loaded successfully from the Global Assembly Cache (GAC)."
+    $asm = [System.Reflection.Assembly]::LoadWithPartialName("Microsoft.UpdateServices.Administration")
+    if ($asm -and (Test-AssemblyLoaded)) {
+        Write-Log "WSUS Administration assembly loaded from GAC via partial name." -Level INFO
+        Show-MessageBox -Message "WSUS Administration assembly loaded from the Global Assembly Cache (GAC)."
         return
     } else {
-        throw "Assembly not loaded from GAC."
+        throw "LoadWithPartialName returned null."
     }
 } catch {
-    Write-Log "Failed to load WSUS assembly from GAC: $_" -Level WARNING
+    Write-Log "Could not load WSUS assembly by partial name: $($_.Exception.Message)" -Level WARNING
 }
 
-# Attempt to load the assembly directly from known GAC path
-if (Test-Path $wsusAssemblyPath) {
+# ---------------- Try 3: Probe known GAC folders and Add-Type ----------------
+$foundPath = $null
+foreach ($root in $GacRoots) {
+    if (-not (Test-Path $root)) { continue }
     try {
-        Add-Type -Path $wsusAssemblyPath -ErrorAction Stop
-        Write-Log "WSUS Administration assembly loaded successfully from $wsusAssemblyPath." -Level INFO
-        Show-MessageBox -Message "WSUS Administration assembly loaded successfully from path:`n$wsusAssemblyPath"
+        $candidate = Get-ChildItem -Path $root -Recurse -Filter "Microsoft.UpdateServices.Administration.dll" -ErrorAction SilentlyContinue | Select-Object -First 1
+        if ($candidate) { $foundPath = $candidate.FullName; break }
+    } catch { }
+}
+
+if (-not $foundPath -and (Test-Path $ExplicitAssemblyPath)) {
+    $foundPath = $ExplicitAssemblyPath
+}
+
+if ($foundPath) {
+    try {
+        Add-Type -Path $foundPath -ErrorAction Stop
+        if (Test-AssemblyLoaded) {
+            Write-Log "WSUS Administration assembly loaded from: $foundPath" -Level INFO
+            Show-MessageBox -Message "WSUS Administration assembly loaded from:`n$foundPath"
+            return
+        } else {
+            throw "Add-Type succeeded but assembly not visible in current AppDomain."
+        }
     } catch {
-        $msg = "Error: Failed to load WSUS assembly from:`n$wsusAssemblyPath`n`nDetails: $_"
+        $msg = "Failed to load WSUS assembly from:`n$foundPath`n`nDetails: $($_.Exception.Message)"
         Write-Log $msg -Level ERROR
         Show-MessageBox -Message $msg -Icon 'Error'
         exit 1
     }
-} else {
-    $msg = "WSUS assembly not found at:`n$wsusAssemblyPath`n`nEnsure the WSUS Administration Console is installed using one of the following methods:`n"
-    $msg += "`n1. Server Manager:`n   - Add Roles and Features > Features > Windows Server Update Services > WSUS Tools"
-    $msg += "`n2. PowerShell:`n   - Install-WindowsFeature -Name UpdateServices-UI"
-    Write-Log "Error: WSUS assembly not found at $wsusAssemblyPath." -Level ERROR
-    Show-MessageBox -Message $msg -Icon 'Error'
-    exit 1
 }
 
+# ---------------- Final guidance (not found) ----------------
+$help = @"
+WSUS Administration assembly was not found.
+
+Install WSUS Management Tools (Administration Console) using one of the following:
+
+1) Server Manager
+   - Add Roles and Features ➜ Features ➜ Windows Server Update Services ➜ WSUS Tools
+
+2) PowerShell (Windows Server)
+   Install-WindowsFeature -Name UpdateServices-UI
+
+3) Windows Client (RSAT on Windows 10/11)
+   DISM /Online /Enable-Feature /FeatureName:Rsat.WSUS.Tools~~~~0.0.1.0 /All
+
+After installing, re-run this script.
+"@
+
+Write-Log "WSUS Administration assembly not found in GAC paths or explicit path." -Level ERROR
+Show-MessageBox -Message $help -Icon 'Error'
+exit 1
+
 # End of script