Windows Update Script (PowerShell) - DigitalFyre Knowledge Base

A PowerShell script that installs the PSWindowsUpdate module and applies all available Windows updates. Supports optional automatic reboot when kernel or driver updates require it.

Prerequisites

The script must be run in an elevated (Administrator) PowerShell session. Right-click PowerShell and select Run as Administrator, or open Windows Terminal as Administrator.

The Script

windows-update.ps1

#Requires -RunAsAdministrator

<#
.SYNOPSIS
    Installs all available Windows updates.
.DESCRIPTION
    Installs the PSWindowsUpdate module if not present, then downloads and
    installs all available updates. Use -AutoReboot to automatically restart
    when required.
.PARAMETER AutoReboot
    Automatically restart the server if updates require it.
#>
param(
    [switch]$AutoReboot
)

$ErrorActionPreference = "Stop"

# Install PSWindowsUpdate module if not already present
if (-not (Get-Module -ListAvailable -Name PSWindowsUpdate)) {
    Write-Host "Installing PSWindowsUpdate module..." -ForegroundColor Cyan
    Install-PackageProvider -Name NuGet -MinimumVersion 2.8.5.201 -Force | Out-Null
    Set-PSRepository -Name PSGallery -InstallationPolicy Trusted
    Install-Module -Name PSWindowsUpdate -Force -Confirm:$false
}

Import-Module PSWindowsUpdate

# Check for available updates
Write-Host "`nChecking for updates..." -ForegroundColor Cyan
$updates = Get-WindowsUpdate

if ($updates.Count -eq 0) {
    Write-Host "No updates available." -ForegroundColor Green
    exit 0
}

Write-Host "Found $($updates.Count) update(s):" -ForegroundColor Yellow
$updates | Format-Table -Property Title, Size, Status -AutoSize

# Install all updates
Write-Host "Installing updates..." -ForegroundColor Cyan
if ($AutoReboot) {
    Install-WindowsUpdate -AcceptAll -AutoReboot
} else {
    Install-WindowsUpdate -AcceptAll -IgnoreReboot
}

# Check reboot status
if (Get-WURebootStatus -Silent) {
    Write-Host "`n*** A reboot is required to complete the update. ***" -ForegroundColor Yellow
    if (-not $AutoReboot) {
        Write-Host "Run 'Restart-Computer' or reboot manually when ready." -ForegroundColor Yellow
    }
} else {
    Write-Host "`nAll updates installed successfully." -ForegroundColor Green
}

Usage

# Save the script and run it
.\windows-update.ps1

# Run with automatic reboot
.\windows-update.ps1 -AutoReboot

:::caution If your PowerShell execution policy blocks scripts, you will need to allow it for the current session:

Set-ExecutionPolicy -ExecutionPolicy RemoteSigned -Scope Process

This only affects the current session and does not change the system-wide policy. :::

Scheduling with Task Scheduler

To run updates on a schedule:

Open Task Scheduler (taskschd.msc)
Create a new task with Run with highest privileges checked
Set the trigger to your preferred schedule (e.g., weekly on Sundays at 3:00 AM)
Set the action to:
- Program: powershell.exe
- Arguments: -ExecutionPolicy Bypass -File "C:\Scripts\windows-update.ps1"

Add -AutoReboot to the arguments if you want the server to reboot automatically after updates.

What PSWindowsUpdate Provides

The PSWindowsUpdate Module is a widely used community module that wraps the Windows Update Agent API. Key commands:

Command	Description
`Get-WindowsUpdate`	List available updates without installing
`Install-WindowsUpdate -AcceptAll`	Download and install all available updates
`Get-WUHistory`	View update installation history
`Get-WURebootStatus`	Check if a reboot is pending

​Prerequisites

​The Script

​Usage

​Scheduling with Task Scheduler

​What PSWindowsUpdate Provides

Prerequisites

The Script

Usage

Scheduling with Task Scheduler

What PSWindowsUpdate Provides