Microsoft: September updates break File History backup feature

September 21, 2026 · BleepingComputer · Severity: MEDIUM

Microsoft warned that the built-in File History backup feature in Windows may stop working on some systems after installing the September 2026 security updates.

Key Takeaways

Microsoft confirmed that the September 2026 security updates break the built-in File History backup feature on some Windows systems.
File History may stop working entirely after installing the updates, leaving users without their configured backup functionality.
Microsoft is expected to release a fix for the File History issue in a future update to restore normal backup operations.