Windows 11 [SOLVED] Win 11 24h2 unattend installation

[raddirad]

Hi,

I work for a company that provides automated OS installations (Windows and Linux) for it's users/customers.

I am having problems to install Win11 24h2 with an unattended installation. After the WinPE part/setup.exe the machine doesn't start and just cycles in the loading icon of the first reboot and does nothing.

The same unattend.xml works fine on Win11 23h2.

The installation procedure: The machine first boots into a linux image, prepartitions the drive, copies files onto the disk (WinPE), patches the unattend.xml and then reboots into the WinPE.

I discovered it must have to do something with the

<ModifyPartitions>

section in my unattend.xml. When I just comment it out or remove it, the installation runs fine. But this isn't a solution as this works good on a single disk and system but will most likely fail on a multidisk system.

This is what the section looks like

Code:

                     <ModifyPartitions>
                         <ModifyPartition wcm:action="add">          
                             <Format>NTFS</Format>          
                             <Label>WINDOWS</Label>          
                             <Letter>C</Letter>          
                             <Order>1</Order>          
                             <PartitionID>3</PartitionID>  
                         </ModifyPartition>      
                         <ModifyPartition wcm:action="add">                      
                             <Label>WINPE</Label>
                             <Letter>X</Letter>
                             <Order>2</Order>
                             <PartitionID>4</PartitionID>
                         </ModifyPartition>
                     </ModifyPartitions>

As we already have a proper partitioning done in the linux bootimage the unattend.xml doesn't need a CreatePartition section.

Within the OOBE we run scripts located on the WinPE partition.

Any suggestion what might cause the issue with 24h2? This works fine on Windows 10 and previous Windows 11 versions

Regards

raddirad

 

[ChatGPT]

Hi raddirad, It seems you're encountering quite the pickle with your unattended installation of Windows 11 24h2. The cycling loading icon after the WinPE phase suggests that something is going awry during either the partition modification or the installation process itself. A few thoughts to consider: 1. ModifyPartitions Section: Since commenting out the section leads to a successful installation, it indicates that the issue likely lies within this section. - Ensure that the PartitionID values you're using (3 and 4) correspond to valid and existing partitions. If there's a mismatch or if the specified partitions are not available at the time of execution, it could cause problems during installation. 2. Order of Operations: Make sure that the partitions defined in your section are actually set up and valid based on your earlier pre-partitioning work in the Linux image. If any changes were made to the partition layout, it could result in referencing incorrect IDs. 3. Logging: Use the Windows setup logs to gather more insights into what might be happening during the installation. You can find setup logs in the C:\Windows\Panther directory. Particularly, the setupact.log and setuperr.log can provide clues to any errors or issues that arise during installation. 4. Compatibility: Double-check if there are any known issues or changes in Windows 11 24h2 that might have altered requirements for unattended installations compared to 23h2. Sometimes, Microsoft introduces enhancements that can inadvertently affect older configurations. 5. Test with Fewer Modifications: As a diagnostic step, try modifying just one partition at a time in your section to isolate which specific modification is leading to the failure. This trial-and-error method can sometimes reveal more information about what's going wrong. 6. Partition Formatting: Though you've indicated that a CreatePartition section is unnecessary, ensure that the formatting (NTFS) and labeling (WINDOWS and WINPE) in your configuration are indeed supported and appropriately timed in the install process. 7. Documentation: Lastly, it may help to review any updated documentation or release notes from Microsoft specifically related to unattended installations for Windows 11 24h2. Sometimes, small changes are documented that can lead to larger impacts in setup processes. Hopefully, one of these pointers nudges you in the right direction. If need be, feel free to share the exact error messages from your logs; they might help pinpoint the exact nature of the issue. Best of luck with your installation, and let me know if you have further questions! Regards, @ChatGPT

 

[raddirad]

After some more digging, leaving out the following section the installation runs fine.
However WINPE is then mounted as drive D. This most probably will change when a data partition is added in the installation process

                         <ModifyPartition wcm:action="add">                       
                             <Label>WINPE</Label>
                             <Letter>X</Letter>
                             <Order>2</Order>
                             <PartitionID>4</PartitionID>
                         </ModifyPartition>

Any suggestion what might cause the issue?
Adding a Format Tag didn't solve it.

Regards
raddirad

 

[ChatGPT]

Hi raddirad,
Thanks for the update! It's good to hear that removing the WINPE modification allowed the installation to proceed, but it raises a couple of other concerns regarding drive lettering and potential conflicts during the process.

Here are some insights and suggestions on the matter:​

1. Drive Letter Assignment: The Windows setup can assign drive letters based on certain criteria, and existing partitions can affect how they are assigned. If WINPE is being mounted as D, it's possible that there are no other fixed drives that could be assigned D first, or it could simply be following the next available letter. When data partitions are added, this sequence can change and lead to conflicts.
   • If your installation's functionality relies on specific drive letters (especially if scripts or applications expect WINPE to be on X), this can complicate things significantly.
2. Use of Format Tag: The absence of the tag in the ModifyPartition for WINPE typically means it assumes a pre-existing partition format. However, since you noted that adding a format tag didn't help, it could suggest that the actual issue lies elsewhere rather than simply needing the partition formatted.
   
   • Testing with Alternative Drive Letter: Try changing the drive letter for WINPE in your unattend file to see if using a different letter (like Y or Z) alters the installation behavior. This could help determine if it's a drive-letter conflict causing installation issues.
   • Log Investigation: As mentioned earlier, checking the logs is always helpful. Specifically, look into the logs right after the partition modification steps to see if any errors or warnings are generated that might point to a specific problem with the WINPE partition modification.
   • Consideration for Multi-Partition Setup: Given that you're integrating an unattended installation in a multi-partition environment, it may be wise to carefully review how partitions are being managed in the setup process. If possible, consider sequencing your scripts/actions in a way that minimizes potential conflicts or reassesses how partitions are being introduced during the OOBE phase.
   • Alternative Partitioning Approach: If there are further complications with the current approach, it might be worth exploring whether there's a possibility to utilize CreatePartition with Format at a strategic moment that ensures WINPE is configured robustly just before it is needed.
   • Microsoft Communities: Lastly, if the problem persists and you cannot find documentation addressing your specific case, it may be beneficial to check out Microsoft Communities or other forums dedicated to Windows deployment to see if others have faced similar issues with 24h2.

Feel free to keep me posted on your findings or if you encounter further hurdles. I'm here to help!

 

[raddirad]

So the issue itself is resolved.

It seems that a partition cannot have the same drive letter as the WinPE ramdisk, as it was in my case.
Setting the letter to anything other than "X" solved the issue.

 

[ChatGPT]

Hi raddirad,
Fantastic news on resolving the issue! It's quite common for drive letter conflicts to throw a wrench into the works, especially in deployment scenarios where multiple partitions are involved.

Key Takeaways for Future Reference:​

1. Drive Letter Conflicts: As you discovered, it's crucial to ensure that the assigned drive letters for partitions do not overlap with those used by system-reserved drives, such as the WinPE ramdisk, which is typically assigned X. This can lead to conflicts that halt the installation process.
2. Flexibility with Letters: As you successfully did, using drive letters other than X (like Y or Z) for your additional partitions can help sidestep these issues. It's always a best practice to have a clear mapping of what letters might be used during installation.
3. Documenting Changes: It might be beneficial to document this specific behavior as a best practice for future installations of Windows 11, especially in automated or unattended scenarios. This can be valuable not only for you but also for colleagues or others in your field who may face similar issues.

If you have any more questions about the unattended installation process or anything else, feel free to reach out. Congratulations again on sorting this out!
Best regards,
[Your Name]