Has File History been disabled again?

File History has not been disabled in Windows 11, but the first step is to determine whether this is a general File History failure or only the Outlook data file being omitted.

1. Test File History with another file

1. Create or modify a small file in Documents.
2. Open Control Panel → System and Security → Save backup copies of your files with File History.
3. Select Run now.
4. Browse the File History destination and check whether the newly changed file is present. Search by its filename rather than relying only on the displayed Last backup date.

File History automatically covers libraries and folders such as Documents, Pictures, Videos, and Desktop. A folder elsewhere is not necessarily protected unless it has been added to a library.^1^

• If neither the test file nor the Outlook file is backed up: continue with the Windows update check below.
• If the test file is backed up: File History is operating, so concentrate on the Outlook file’s location and type.

2. Check the Outlook file’s location and type

Determine whether the file is a .pst or .ost, and note its complete path.

• In new Outlook, go to Settings → Files → Outlook Data Files to see configured PST files.^2^
• In classic Outlook, the data-file settings are available under File → Account Settings → Account Settings → Data Files.

Then check the path:

• If the containing folder is outside Documents, Desktop, or another protected library, right-click that folder in File Explorer and select Show more options → Include in library, then choose or create a library. Run File History again.^1^
• If it is an .ost, it is normally a synchronized offline data file rather than a standalone Outlook archive. Identify whether the November 6 backup was actually a PST before comparing results.
• As a diagnostic, close Outlook completely before running File History again, so the data file is not actively being changed.

Do not move an Outlook PST onto the File History drive and use it there as the live data file. Microsoft documents that remotely accessed PST files can perform poorly and may become corrupted if the connection fails.^3^

3. Check the Windows build and update level

Open:

1. Settings → System → About and record Version and OS build.
2. Settings → Windows Update → Update history and record the latest cumulative update.

Windows 11 versions 24H2, 25H2, and 26H2 had a documented general File History problem in September 2026. Microsoft addressed it in KB5124010, OS builds 26100.9550, 26200.9550, and 26300.9550, respectively.^4^

If your build predates that update:

1. Go to Settings → Windows Update.
2. Select Check for updates.
3. Install the latest cumulative update offered for your Windows version.
4. Restart and repeat the test-file and Outlook-file checks.

That fix addressed broader failures involving external drives or network locations; it does not document a PST-specific exclusion. Reports also describe cases where files were written successfully but File History’s status remained stale.^5^

If files exist but the status is stale

Only if the new files are physically present at the destination but Last backup or Previous Versions is outdated:

1. Open Control Panel → File History → Select drive.
2. Select the current backup drive again.
3. Save the selection and run another backup.

Reselecting the same drive has temporarily refreshed File History’s state in matching reports.^5^

Protect the Outlook data meanwhile

Until File History is confirmed working, close Outlook and copy the PST to separate local or external storage. In new Outlook, another option is Settings → Files → Export → Get started, then select the mailbox or folders to export.^6^

If an in-scope PST remains omitted while other changed files back up, report it through Feedback Hub → Files, Folders, and Online Storage → File History, using Recreate my problem if offered. Include:

• Windows version, OS build, and latest installed KB
• PST path and whether Outlook was closed
• External-drive or network destination
• Whether the Documents test file succeeded
• Logs from Event Viewer → Applications and Services Logs → Microsoft → Windows → FileHistory-Engine

Also contact Microsoft Support if the omission persists; there is currently no separately documented PST-specific File History exclusion.

References

1. Backup and restore with File History | Microsoft Support
2. [Classic Outlook](https://support.microsoft.com/outlook/open-and-close-outlook-data-files-pst)
3. Limits to using personal folders files over LAN and WAN links
4. September 22, 2026—KB5124010 (OS Builds 26300.9550, 26200.9550, and 26100.9550) Preview
5. Files are backed up, but File History status and Previous Versions are not updating after recent Windows updates KB5101684 and KB5120249 - Microsoft Q&A
6. [New Outlook](https://support.microsoft.com/outlook/export-emails-contacts-and-calendar-items-to-outlook-using-a-pst-file)