File History Backup Problems with last security update

Title: File History will not turn on after September 2026 Windows updates

Description:

File History stopped working after the September 2026 Windows updates.

My PC is running Windows 11 Version 25H2, OS Build 26200.9457.

Before the September updates, File History was working normally and was backing up to my external Seagate drive (Expansion F:).

The last successful File History backup was September 4, 2026.

After the September Windows problems and updates, File History reports that the drive needs to be connected even though:

• The Seagate Expansion (F:) drive is connected and works normally in File Explorer.

I can open and access the F: drive normally.

The existing F:\FileHistory folder and previous backups are still present.

Windows File History recognizes Expansion (F:) as the previous File History drive.

The File History service (fhsvc) is running.

Restarting the File History service did not resolve the problem.

The File History "Turn on" button does not actually turn File History on.

Windows updates installed include:

KB5124007 — installed 9/12/2026

KB5126052 — installed 9/12/2026

KB5129195 — installed 9/15/2026

KB5129195 brought the system to build 26200.9457, but File History remains broken.

I have NOT uninstalled the updates because I do not want to remove security updates based solely on an unofficial workaround.

I have also confirmed that the existing File History configuration on the external drive is intact. The local Config1.xml and the Config1.xml on the File History drive are identical.

Please investigate this as a possible Windows 11 25H2 File History regression associated with the September 2026 updates. Other users are reporting the same problem in Microsoft Q&A.

The desired resolution is a Windows update that restores File History functionality without requiring users to roll back security updates or recreate their existing File History backups.

Thank you.Title: File History will not turn on after September 2026 Windows updates

Description:

File History stopped working after the September 2026 Windows updates.

My PC is running Windows 11 Version 25H2, OS Build 26200.9457.

Before the September updates, File History was working normally and was backing up to my external Seagate drive (Expansion F:).

The last successful File History backup was September 4, 2026.

After the September Windows problems and updates, File History reports that the drive needs to be connected even though:

The Seagate Expansion (F:) drive is connected and works normally in File Explorer.

I can open and access the F: drive normally.

The existing F:\FileHistory folder and previous backups are still present.

Windows File History recognizes Expansion (F:) as the previous File History drive.

The File History service (fhsvc) is running.

Restarting the File History service did not resolve the problem.

The File History "Turn on" button does not actually turn File History on.

Windows updates installed include:

KB5124007 — installed 9/12/2026

KB5126052 — installed 9/12/2026

KB5129195 — installed 9/15/2026

KB5129195 brought the system to build 26200.9457, but File History remains broken.

I have NOT uninstalled the updates because I do not want to remove security updates based solely on an unofficial workaround.

I have also confirmed that the existing File History configuration on the external drive is intact. The local Config1.xml and the Config1.xml on the File History drive are identical.

Please investigate this as a possible Windows 11 25H2 File History regression associated with the September 2026 updates. Other users are reporting the same problem in Microsoft Q&A.

The desired resolution is a Windows update that restores File History functionality without requiring users to roll back security updates or recreate their existing File History backups.

Thank you.