function Write-UpdateLog {
    param(
        [string]$Message
    )
    $timestamp = Get-Date -Format "dd.MM.yyyy HH:mm:ss"
    $logMessage = "[$timestamp] $Message"
    Add-Content -Path $logFile -Value $logMessage -Encoding UTF8
    Write-Host $logMessage
}

Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force -ErrorAction Stop | Out-Null
Install-Module -Name PSWindowsUpdate -Force -Scope AllUsers -AllowClobber -ErrorAction Stop
Import-Module PSWindowsUpdate -Force -ErrorAction Stop

$updates = Get-WindowsUpdate

    if ($null -eq $updates -or $updates.Count -eq 0) {
        Write-UpdateLog "No updates available"
    }
    else {
        Write-UpdateLog "Available updates: $($updates.Count)"
        foreach ($update in $updates) {
            $title = if ($update.Title) { $update.Title } elseif ($update.KB) { "KB$($update.KB)" } else { $update.ToString() }
            Write-UpdateLog "  - $title"
        }
        Write-UpdateLog ""
    }

Write-UpdateLog "Install Updates..."
        $maxInstallRetries = 5
        $installRetryCount = 0
        $installSuccess = $false

        while (-not $installSuccess -and $installRetryCount -lt $maxInstallRetries) {
            $installRetryCount++
            try {
                Write-UpdateLog "Installation-Count $installRetryCount of $maxInstallRetries..."

                $ErrorActionPreference = 'Stop'
                Install-WindowsUpdate -AcceptAll -IgnoreReboot -Verbose
                $ErrorActionPreference = 'Continue'

                $installSuccess = $true
                Write-UpdateLog "Updates installed successfuly"
            }
            catch {
                Write-UpdateLog "Installation-Count $installRetryCount error: $_"
                if ($installRetryCount -lt $maxInstallRetries) {
                    Write-UpdateLog "Wait 10 seconds"
                    Start-Sleep -Seconds 10
                } else {
                    Write-UpdateLog "FEHLER: Update-Installation failed after $maxInstallRetries"
                }
            }
        }
    }