Microsoft has informed users that File History, the built-in backup feature in Windows since Windows 8, may no longer create or update backups on certain computers after the installation of the September 2026 security updates. This feature typically backs up essential user data such as the Desktop, Documents, Images, Music, and Videos, usually stored on a USB drive or network share. Users have reported issues where the backup process stops functioning entirely, even when the external storage device is connected and working. Microsoft has transitioned File History to a new feature called Windows Backup, which relies on OneDrive for cloud-based storage. However, File History can still be accessed through the Control Panel. Affected users are experiencing symptoms that mimic hardware failure, as Windows repeatedly prompts them to reconnect the backup drive, even when it is properly connected. The last backup date remains unchanged, and no previous versions of files are accessible. Technical logs show that the FileHistory.exe and KERNELBASE.dll components are crashing, leading to the backup failure. The issue affects a range of Windows versions, including Windows 11 since the 23H2 update, Windows 10 since the 21H2 update, and Enterprise LTSC 2016 and 2019 editions. According to a Microsoft support thread, the only confirmed workaround is to uninstall the September 2026 update and disable automatic Windows Update updates until a fix is available. However, this update addresses several critical security vulnerabilities, including some that are actively being exploited, so disabling it may leave systems more exposed to attacks. Microsoft is currently investigating the problem and hopes to release a fix in an upcoming update. In the meantime, users can consider alternative backup tools like FreeFileSync, Kopia, and restic, which create encrypted backups of files and folders to local storage, network drives, or the cloud. These tools often include features like compression and deduplication to save space. However, they do not provide the same convenient features as File History, such as the ability to easily access previous versions of files directly from the file explorer.