fetch and install Windows Updates using COM API objects in powershell

script.ps1

# Copy and paste this script into an admin powershell window
# or download it and call it with powershell.exe -ExecutionPolicy Bypass -File /path/to/script.ps1

# API documentation can be found at https://learn.microsoft.com/en-us/windows/win32/wua_sdk/portal-client

# Create a Windows Update session and searcher
$Session = New-Object -ComObject Microsoft.Update.Session
$Searcher = $Session.CreateUpdateSearcher()

# Search for updates with progress
Write-Progress -Activity "🔍 Checking for updates..." -Status "Initializing search"
$SearchResult = $Searcher.Search("IsInstalled=0 and Type='Software'")
Write-Progress -Activity "🔍 Checking for updates..." -Completed

if ($SearchResult.Updates.Count -gt 0) {
    # Prepare the update collection for later reference
    $UpdatesToInstall = $SearchResult.Updates

    # Display update list
    Write-Host "✅ Found $($UpdatesToInstall.Count) updates:"
    for ($i = 0; $i -lt $UpdatesToInstall.Count; $i++) {
        $update = $UpdatesToInstall.Item($i)
        $kb = if ($update.KBArticleIDs.Count -gt 0) { $update.KBArticleIDs -join ", " } else { "N/A" }
        Write-Host "   - [KB$kb] $($update.Title)"
    }

    # Download updates with progress
    $Downloader = $Session.CreateUpdateDownloader()
    $Downloader.Updates = $UpdatesToInstall
    Write-Progress -Activity "⬇️ Downloading updates..." -PercentComplete 0 -Status "Preparing"
    
    try {
        $DownloadResult = $Downloader.Download()
        Write-Progress -Activity "⬇️ Downloading updates..." -Completed

        # Map ResultCode to a friendly message
        $downloadStatus = switch ($DownloadResult.ResultCode) {
            2 { "✅ Succeeded" }
            3 { "⚠️ Succeeded with errors" }
            4 { "❌ Failed" }
            5 { "⏹️ Aborted" }
            default { "❓ Unknown result ($($DownloadResult.ResultCode))" }
        }
        Write-Host "`n💾 Download status: $downloadStatus"

        # Optional: Show per-update download status (if supported)
        if ($DownloadResult.PSObject.Methods.Name -contains "GetUpdateResult") {
            Write-Host "`n📥 Per-update download results:"
            for ($i = 0; $i -lt $UpdatesToInstall.Count; $i++) {
                $update = $UpdatesToInstall.Item($i)
                $result = $DownloadResult.GetUpdateResult($i)
                $status = switch ($result.ResultCode) {
                    2 { "✅ Succeeded" }
                    3 { "⚠️ Succeeded with errors" }
                    4 { "❌ Failed" }
                    5 { "⏹️ Aborted" }
                    default { "❓ Unknown" }
                }
                $kb = if ($update.KBArticleIDs.Count -gt 0) { $update.KBArticleIDs -join ", " } else { "N/A" }
                Write-Host "   - $status [KB$kb] $($update.Title)"
            }
        }
    }
    catch {
        Write-Host "❌ Download failed: $($_.Exception.Message)"
        exit
    }

    # Install updates with per-update tracking
    $Installer = $Session.CreateUpdateInstaller()
    $Installer.Updates = $UpdatesToInstall
    $totalUpdates = $UpdatesToInstall.Count

    Write-Host "`n🔧 Installing updates:"
    for ($i = 0; $i -lt $totalUpdates; $i++) {
        $update = $UpdatesToInstall.Item($i)
        $kb = if ($update.KBArticleIDs.Count -gt 0) { $update.KBArticleIDs -join ", " } else { "N/A" }
        $percent = [math]::Round((($i+1) / $totalUpdates) * 100)
        Write-Progress -Activity "⚙️ Installing updates..." -Status "$($i+1)/$totalUpdates" `
            -PercentComplete $percent -CurrentOperation "Installing: $($update.Title)"
    }

    $InstallResult = $Installer.Install()
    Write-Progress -Activity "⚙️ Installing updates..." -Completed

    # Display installation results
    Write-Host "`n📊 Installation results:"
    for ($i = 0; $i -lt $UpdatesToInstall.Count; $i++) {
        $result = $InstallResult.GetUpdateResult($i)
        $update = $UpdatesToInstall.Item($i)
        $status = switch ($result.ResultCode) {
            2 { "✅ Succeeded" }
            3 { "⚠️ Succeeded with errors" }
	        4 { 
            # Convert HResult to hexadecimal format (e.g., 0x80050007)
            $hexError = "0x{0:X8}" -f $result.HResult
            "❌ Failed (Error: $hexError)" 
        }
            5 { "⏹️ Aborted" }
            default { "❓ Unknown" }
        }
        $kb = if ($update.KBArticleIDs.Count -gt 0) { $update.KBArticleIDs -join ", " } else { "N/A" }
        Write-Host "   - $status [KB$kb] $($update.Title)"
    }

    # Reboot handling
    if ($InstallResult.RebootRequired) {
        Write-Host "`n🔄 System reboot required!"
        $choice = Read-Host "Restart now? (Y/N)"
        if ($choice -eq 'Y') { Restart-Computer -Force }
    }
} else {
    Write-Host "🎉 No updates available!"
}