Automating Windows Installation with Autounattend.xml and UUP dump

Automating a Windows unattended installation can save hours of repetitive work — whether for lab testing, VM deployment, or mass corporate rollout. By using an Autounattend.xml file, you predefine installation steps such as language, partitioning, product key, and even post-install configuration, all without user input.

In this guide, you’ll learn:

1. What Autounattend.xml is and how it works
2. How to create it
3. How and where to place it
4. How to integrate language packs
5. How to use UUP dump for building custom ISOs
6. Example: fully automated workflow
7. Troubleshooting common issues

1. Understanding Autounattend.xml

Autounattend.xml is a Windows answer file that automates setup by supplying preconfigured values.

Phases (passes) it controls:

• windowsPE — disk partitioning, language, TPM/Secure Boot bypass
• specialize — drivers, hostname, networking
• oobeSystem — accounts, privacy, first-run experience

Common settings include:

• Language and locale
• Disk layout and formatting
• Edition selection (from install.wim/install.esd)
• Product keys
• Driver injection
• Registry tweaks and PowerShell scripts

When Windows Setup detects Autounattend.xml, it follows the specified configuration automatically.

2. Creating Autounattend.xml

Option 1: Windows SIM (System Image Manager)

• Part of Windows ADK
• Loads an install.wim and provides a GUI for configuring settings
• Validates before saving
• Download: Windows ADK

Option 2: Online Generators

• Example: Schneegans Generator
• Offers quick form-based setup for:
  • Language
  • Disk layout
  • User accounts
  • TPM/Secure Boot bypass
• Produces ready-to-use XML

Option 3: Manual Editing

• Edit with VS Code, Notepad++, etc.
• Follow the Unattended Setup Reference
• Always validate with Windows SIM

3. Placing Autounattend.xml

Windows Setup searches multiple locations:

A. Root of USB

• Plug in a USB with only Autounattend.xml
• Works with official ISOs
• Requires 2 devices

B. Integrated into ISO

• Mount ISO → Copy contents → Place XML in root → Rebuild ISO
• Windows (ADK):

  1	oscdimg -m -o -u2 -udfver102 C:\WinISO C:\Win11-Auto.iso

• Linux:

  1	mkisofs -b boot/etfsboot.com -no-emul-boot -boot-load-size 8 -o Win11-Auto.iso WinISO/

Tip: use oscdimg on Windows, mkisofs on Linux.

C. Second Virtual CD/DVD

• Attach small ISO with Autounattend.xml as secondary media in VM
• Avoids editing original ISO

D. $OEM$ Structure

• Place in sources\$OEM$\$1
• Common in OEM factory setups

Note: Windows scans all connected drives, prioritizing removable media.

4. Integrating Language Packs

1. Download .cab packages:
   • Microsoft-Windows-Client-Language-Pack_x64_<lang>.cab
   • Microsoft-Windows-LanguageFeatures-Basic-<lang>-Package.cab
2. Inject with DISM:

   1 2 3

   dism /Mount-Wim /WimFile:install.wim /Index:1 /MountDir:mount dism /Image:mount /Add-Package /PackagePath:lp.cab dism /Unmount-Wim /MountDir:mount /Commit

3. Update Autounattend.xml <UILanguage>, <SystemLocale>, <InputLocale>

Tip: If you use UUP dump and select the desired language during build, you can skip manual integration.

5. Using UUP dump

UUP dump — a tool to download official Microsoft Windows builds from UUP servers with custom options.

Overview

• Any Windows version (11, 10, Server)
• Edition & language selection
• Language packs & Features on Demand
• Always latest builds from Microsoft CDN

Converter Scripts

• convert-UUP.cmd (Windows)
• convert.sh (Linux/macOS)

Functions:

• Assemble ISO from UUP files
• Integrate updates, drivers, language packs

Example (Linux):

1
2

sudo apt install aria2 cabextract wimtools chntpw genisoimage
./convert.sh wim

6. Automated Workflow Example

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UUP dump → ISO Build → Add Autounattend.xml → (Optional) Add Language Packs → Deploy

1. UUP dump — Select build, edition, language → Download script
2. Convert — Run convert.sh or convert-UUP.cmd to get ISO
3. Integrate XML — Place in root of ISO or separate ISO
4. Optional: Inject language packs
5. Deploy — Boot and enjoy unattended setup

Example Linux one-liner:

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./uup_download_linux.sh && cp Autounattend.xml iso-root/ && mkisofs -o Win11-Auto.iso iso-root/

7. Troubleshooting Common Errors

XML Parse Error

• Validate in Windows SIM
• Check for unsupported elements

File Not Found

• Ensure exact filename Autounattend.xml
• Place in root of media

Driver Missing

• Inject via DISM before install

Language Not Applied

• Match <UILanguage>, <UserLocale>, <SystemLocale> with installed pack

TPM/Secure Boot Block

• Add registry bypass in windowsPE

Endless Reboot

• Simplify XML
• Match partition layout to boot mode

Logs:

• X:\Windows\Panther\setuperr.log
• X:\Windows\Panther\setupact.log

8. Why Use This

Combining Autounattend.xml + UUP dump lets you:

• Build fully automated ISOs
• Preconfigure language, edition, updates
• Save time in repetitive installations
• Maintain consistent environments for VMs, labs, and bare-metal deployments