Windows update bug broke some PC backups, but Microsoft has now fixed it
Microsoft fixed a problem that caused the built-in Windows File History backup tool to stop working properly on some computers after recent updates. People who rely on this feature should make sure their system is updated so backups work as expected again.
Who is at risk
Windows users who use File History to back up personal files are most at risk, especially if they installed the affected September 2026 updates.
What to watch for
Watch for missing recent backups, backup errors, or signs that File History has stopped saving copies of your files.
What to do
Install the latest Windows updates now, then check that File History is turned on and successfully creating new backups.