Microsoft confirms Windows 11 quietly stopped backing up your files due to a new bug in September 2026 update
windowslatest.com Sep 23, 2026

Microsoft confirms Windows 11 quietly stopped backing up your files due to a new bug in September 2026 update

AI-summarised brief · reviewed before publication

Microsoft confirmed that the September 2026 Windows 11 update (KB5124008) introduced a bug that disables File History backups for most users. The feature, which automatically backs up libraries to external or network drives, now fails to recognize connected drives and shows incorrect timestamps. Microsoft acknowledged the issue on September 22, noting false “reconnect your drive” alerts and potential crashes of FileHistory.exe. The problem affects nearly all installations of the 25H2 and 24H2 builds.

💡 Why It Matters

  • · Users relying on File History for data protection are suddenly left without a reliable backup mechanism, risking accidental data loss.
  • · The bug undermines a core Windows 11 feature that many depend on for file recovery.