Microsoft has fixed a bug that caused the built-in File History backup feature to stop working on some Windows computers after the September 2026 security update. The issue affected users who depended on File History to automatically keep copies of important files. File History can save files from folders such as Documents, Music, Pictures, Videos and Desktop to an external drive or network storage location. This allows users to restore older versions of files if they are accidentally deleted or damaged.
The problem appeared after users installed the September 2026 Windows security update, including KB5124008 for Windows 11 24H2 and 25H2. On affected computers, File History could fail to create or update backups even when the backup drive was properly connected and working. Windows could also incorrectly show a “Reconnect your drive” message. In some cases, the Last Backup time would stop updating and previously backed-up files could show “No previous version available.”
Microsoft also confirmed that some affected systems could record application crashes connected to FileHistory.exe and KERNELBASE.dll in Event Viewer. The issue was reported across supported Windows versions, with Microsoft documenting the problem as a known issue in its Windows update information. This meant that users could believe their files were being backed up while File History was actually unable to create or update the required backup copies. The problem mainly affected the backup and restore functions rather than deleting existing files.
The fix is now available through optional September preview updates for Windows 11. Microsoft released KB5124010 for Windows 11 versions 24H2 and 25H2, while KB5124006 provides the fix for Windows 11 version 26H1. Microsoft says these updates address the issue where File History could fail to back up or restore files to an external drive or network location. The updates also correct the incorrect “Reconnect your drive” message that could appear even when the drive was connected and working normally.
Because these are optional preview updates, users who want the File History fix immediately need to install the applicable update through Windows Update. Microsoft says the updates can be found under Settings, Windows Update, Advanced options and Optional updates. Users who do not install the preview update can wait for the fix to arrive through the regular Windows update cycle. Microsoft is expected to include the File History fix in the October 2026 Patch Tuesday updates.
The File History problem shows how a regular Windows update can sometimes create unexpected issues with existing system features. Microsoft has already been addressing several problems linked to the September updates, including issues involving Hyper-V, Remote Desktop Services and USB audio devices. For users who rely on File History, checking that backups are actually updating is important rather than assuming the feature is working normally. After installing the appropriate fix, users should verify that File History successfully creates backups and that older file versions are available for recovery.
Stay alert, and keep your security measures updated!
Source: Follow cybersecurity88 on X and LinkedIn for the latest cybersecurity news
