About UWF settings in Windows11 LTSC environment

Question

I was using the Unified Write Filter with the following settings in a Windows 10 LTSB 1809 environment.

This worked fine, but when I used the same filter in Windows 11 LTSC 2024,

automatic recovery occurred frequently at boot time and it was not usable.

When I added C:\Windows to the excluded folders for investigation, the problem stopped immediately,

so I think it is necessary to register an exception for some file or folder. Since this is to prevent a sudden power cut, it is meaningless to exclude the entire Windows folder. Do you know the target file or folder?

-When an automatic recovery error occurred, it said to refer to System32\LogFiles\Srt\SrtTrail.txt,

but this file did not exist.

-Automatic recovery errors occur frequently, but not 100% of the time. Startup → reboot → automatic recovery

occurred about 80% of the time.

• The filter itself will function, and any files or folders edited before launch will be restored the next time.
• If you stop the filter with uwfmgr filter disable, the auto-recovery error will not occur.status.txt

Answer 1

Hello

It sounds like you're encountering a tricky issue with the Unified Write Filter (UWF) in Windows 11 LTSC 2024. Here are a few steps and considerations that might help you resolve the problem:

 

Common Exclusions: According to Microsoft's guidelines, certain files and folders should not be excluded as it can lead to unpredictable results. However, you can exclude specific subdirectories and files under these locations. For example, excluding the entire C:\Windows folder is not recommended, but you might need to exclude specific files or subdirectories within it.

 

Potential Target Files/Folders: Based on your description, it seems like the issue might be related to system files that are critical during boot. Some common files that might need to be excluded include:

C:\Windows\System32\config\SYSTEM

C:\Windows\System32\config\SOFTWARE

C:\Windows\System32\config\SECURITY

C:\Windows\System32\config\SAM

C:\Windows\System32\config\DEFAULT

C:\Windows\BOOTSTAT.DAT

%SystemDrive%\EFI\Microsoft\Boot\BOOTSTAT.DAT

%SystemDrive%\Boot\BOOTSTAT.DAT

 

Investigate Logs: Since the SrtTrail.txt file did not exist, you might want to check other logs in the C:\Windows\System32\LogFiles directory for any clues. Additionally, reviewing the Event Viewer logs under Windows Logs -> System might provide more insights into what is causing the automatic recovery.

 

Testing Exclusions: You can try adding exclusions one by one to identify the specific file or folder causing the issue. Use the command:

uwfmgr.exe file add-exclusion <path>

After adding each exclusion, restart the system to see if the issue persists.