Microsoft's September Update Just Broke File History Backup

Robert Moore · 2026-09-21

Microsoft just dropped a bombshell for Windows users. The September 2026 security updates are causing the built-in File History backup feature to fail on some systems. If you rely on File History to keep your documents safe, you might be in for a nasty surprise. File History has been a trusty sidekick for Windows users since Windows 8. It automatically backs up your files to an external drive or network location, letting you restore previous versions if something goes wrong. But now, after installing the latest security patches, some users are finding that File History simply stops working. No warning, no error message—just silence. ### Why This Matters More Than You Think We all know that sickening feeling when you realize a file is gone forever. Maybe you accidentally deleted an important report, or ransomware encrypted your entire drive. That's where File History shines—it's your safety net. But if that net has a hole in it, you're falling without a parachute. Microsoft hasn't released a full list of affected systems, but early reports suggest it's not an isolated issue. Users on various Windows versions, including Windows 10 and 11, have reported problems. The update seems to interfere with how File History communicates with external drives, causing backups to stall or fail entirely. > "I didn't notice until I tried to restore a file and realized my last backup was from three months ago," one user wrote on a Microsoft support forum. "That's a lot of work down the drain." That's the real danger here: you might not know your backups are broken until you actually need them. And by then, it's too late. ### What You Can Do Right Now First, don't panic. There are steps you can take to protect yourself while Microsoft works on a fix. - **Check your File History status.** Open the Control Panel, go to File History, and see if it's still running. If it says "File History is off" or shows an error, you're affected. - **Manually verify your backups.** Don't just trust that it's working—open your backup drive and check the date of the most recent files. If they're older than a few days, something's wrong. - **Use an alternative backup method temporarily.** Cloud services like OneDrive or Google Drive can fill the gap. Or use a third-party backup tool that doesn't rely on File History. - **Consider delaying the update.** If you haven't installed the September 2026 updates yet, you might want to hold off until Microsoft confirms a fix. But be aware that skipping security updates comes with its own risks. Microsoft has acknowledged the issue and says it's investigating. In the meantime, they recommend using System Restore or reinstalling the update if you're experiencing problems. But that's cold comfort if you've already lost data. ### The Bigger Picture: Don't Rely on One Backup This whole mess is a reminder that you should never depend on a single backup solution. Even the most reliable tools can break. The golden rule is the 3-2-1 strategy: three copies of your data, on two different types of media, with one copy off-site. So, what's the takeaway? Stay vigilant. Check your backups regularly. And maybe keep an eye on Microsoft's support page for updates. Your files are worth it. We'll keep you posted as more details emerge. In the meantime, stay safe out there—and back up like your data depends on it. Because it does.