Bug Blog

Earlier this month, Microsoft halted the rollout of the latest Windows 10 update after users reported major personal data losses after installing the update, advising anyone who had already downloaded the update to delete it without installing—a significant and unusual move for the company.

Users on Reddit and Microsoft forums posted warnings that the latest update—Windows 10 version 1809—deleted files from their Documents and Pictures folders, the default locations for saving files in the Windows operating system. There did not appear to be a consistent or explicable trigger for this bug; some users described updating multiple systems at once and only experiencing data loss on a few of them.

While the nature of the bug wasn't immediately clear, it shouldn't have come as a surprise to Microsoft, and some are wondering why the update was released at all. Feedback Hub, the bug-reporting tool Microsoft uses for Windows 10, contained multiple complaints about data loss after installing preview releases of the update, some going back as far as three months before the public rollout.

It's unclear why Microsoft did not take any apparent action to fix the bug when the early reports starting coming in through the Feedback Hub. The company did lay off most of its dedicated software testers in 2014, prior to the release of Windows 10, and has relied more on developer testing and user reporting from the Feedback Hub for finding bugs.

On Twitter, former Microsoft engineer Hal Berenson speculated that Microsoft "put in a fix, but it didn't fix all cases," adding: "I've seen that happen many times in my career."

Earlier this year, Windows 10 had issues with bugs causing system freezes and the infamous Blue Screen of Death. These, too, appear to have been reported on the Feedback Hub well before Microsoft took action to fix them.

At this point, update 1809 is still on hold. Users who lost files to the update may have some luck restoring them with file recovery/undelete programs, but the only guaranteed way to bring them back is to restore them from a backup. In a blog post about the update and its issues, Microsoft stated that they have made improvements to the Feedback Hub to help it better detect serious problems in the future.