Modify the Windows 11 IoT LTSC 24H2 ISO image language

Question

Good morning, I would like to ask for help making some changes to the Win 11 IoT LTSC 24H2 ISO image downloaded from the official Microsoft website. It is only available in English US. I need to change it to Spanish Mexico. I managed to install the es-MX language pack, but I had two problems and I would like to know if it is possible to fix them, please:

1.- When I start the ISO already modified with the es-MX language, the first option is US English. I have to manually select es-MX to change it.

Is there a way to set the es-MX language as the default so that the installation always starts with that language and leaves US English as the secondary language?

2.- When I enter Repair my computer in the Windows installation of this ISO, it takes me to the Recovery Menu, but even though I select the Spanish Mexican language, it still appears in English US. Is there a way to set the recovery menu language to es-MX? Or can it be configured so that when I select the es-MX language, the recovery menu changes to es-MX, and when I select English/US, it also changes to English US?

I appreciate the help. Another option would be to install Windows 11 IoT LTSC 24H2 in English, and once installed, download and install the Mexican Spanish language pack. However, in my last post and other posts, it was reported that the Windows 11 24H2 version is having issues when changing languages. I managed to more or less solve this problem as I mentioned in my post, but it doesn't always work on all computers, and I want to try changing the language of the Windows 11 IoT LTSC 24H2 ISO downloaded from the official Microsoft website.

Thanks for the help and attention. 👍

Answer 1

Hi IdeDx,

To modify the Windows 11 IoT LTSC 24H2 ISO to default to Spanish Mexico (es-MX) and fix the recovery environment language, follow these structured steps:

---

Step 1: Prepare Tools and Files

1. Download Required Tools:
   • NTLite (Free trial supports basic modifications)
   • DISM++
   • UltraISO or any ISO editor
2. Get Language Files:
   • Download the official es-MX language packs for 24H2:
     • WinPE (Setup Environment): Microsoft-Windows-WinPE-LanguagePack-Package_es-mx.cab
     • Full OS: Microsoft-Windows-Client-Language-Pack_x64_es-mx.cab
   • Source: Extract from a multi-language ISO or download via Microsoft Update Catalog (search "Windows 11 24H2 amd64 language pack").

---

Step 2: Modify Setup Default Language (boot.wim)

Goal: Force setup to start in Spanish Mexico by default.

1. Extract ISO → Open \sources\boot.wim in NTLite.
2. Load Index 1 (Windows Setup GUI):
   • Add WinPE es-MX CAB under Packages → Apply.
   • Set default language:

     
          dism /image:C:\Mount /Set-SKUIntlDefaults:es-MX
     
     

3. Load Index 2 (WinPE Recovery):
   • Repeat language pack integration.
4. Rebuild boot.wim → Replace in ISO.

---

Step 3: Set OS Default Language (install.wim)

Goal: Ensure installed OS uses es-MX.

1. Open \sources\install.wim in NTLite.
2. Add Full Language Pack:
   • Integrate Client-Language-Pack es-MX CAB.
3. Set Defaults:

   
      # Mount image
   
      dism /Mount-Image /ImageFile:install.wim /Index:1 /MountDir:C:\Mount
   
      # Set language defaults
   
      dism /Image:C:\Mount /Set-SKUIntlDefaults:es-MX
   
      dism /Image:C:\Mount /Set-AllIntl:es-MX
   
      dism /Image:C:\Mount /Gen-LangINI /distribution:C:\ISO\Sources
   
      # Unmount
   
      dism /Unmount-Image /MountDir:C:\Mount /Commit
   
   

4. Edit \sources\lang.ini:

   
      [Available UI Languages]
   
      es-MX = 10  ; Ensure higher priority than en-US
   
      en-US = 3
   
      [Default UI Language]
   
      = es-MX
   
   

---

Step 4: Fix Recovery Environment (winre.wim)

Goal: Translate WinRE to Spanish.

1. Extract WinRE from mounted install.wim:
   • Path: Windows\System32\Recovery\winre.wim
2. Modify with DISM++:
   • Mount winre.wim → Add WinPE es-MX CAB.
   • Set default language:

     
          [HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\MUI\UILanguages]
     
          "es-MX"=hex(7):00
     
     

3. Repack & Replace:
   • Save modified winre.wim back to install.wim and ISO.

---

Step 5: Rebuild ISO

1. Update Files:
   • Replace modified boot.wim, install.wim, and lang.ini in \sources.
2. Repackage ISO with UltraISO:
   • Save as UDF format, preserve boot sectors.

---

Verification Checklist

| Component | Action | Tool Used |

|---------------------|--------------------------------------------|------------------|

| Setup (boot.wim) | Set es-MX as first language | NTLite + DISM |

| OS (install.wim) | Default user/profile to es-MX | DISM |

| Recovery (winre.wim)| Full Spanish UI | DISM++ |

| ISO Structure | Bootable UDF with updated lang.ini | UltraISO |

---

Critical Notes

1. Language Pack Compatibility:
   • Ensure CABs match 24H2 build 26100.1 (exact version required).
2. WinRE Dependencies:
   • Add WinPE fonts (winpe-font-*.cab) to prevent missing glyphs in recovery.
3. Testing:
   • Validate in Hyper-V before deployment:

     
          New-VM -Name "LTSC-Test" -MemoryStartupBytes 4GB -NewVHDPath "C:\VHDs\LTSC.vhdx" -NewVHDSizeBytes 40GB
     
     

---

Alternative: Post-Installation Fix (If ISO Mod Fails)

1. Install in English → Add es-MX via:

   
      # Download language pack
   
      Add-AppxPackage -Path "https://software-static.download.prss.microsoft.com/.../es-mx.lp.cab"
   
      # Set defaults
   
      Set-WinSystemLocale -SystemLocale es-MX
   
      Set-WinUILanguageOverride -Language es-MX
   
   

2. Force WinRE Regeneration:

   
      reagentc /disable
   
      reagentc /enable
   
   

---

By following these steps, the ISO will default to Spanish Mexico during setup and recovery. For persistent language issues in 24H2, consider deploying the latest cumulative update (KB5039302+) which resolves locale bugs.

Please feel free to let me know if you still have any questions.

Best regards,

BblytheX