Microsoft deletes deleterious file deletion bug from Windows 10 October 2018 Update

When the October 2018 Update was installed the original "old" folder was deleted including the files in that folder (in this example c:\users\username\documents would be deleted; d:\documents, the new location, would be preserved). "We will carefully study the results, feedback, and diagnostic data from our Insiders before taking additional steps towards re-releasing more broadly", Cable said.

The world now knows why last week's Microsoft Windows 10 upgrade deleted unlucky users' files: the software treated the default user directory as ripe for destruction, because it thought the files were elsewhere.

An updated version of the Windows 10 October 2018 Update is distributed to Insider Channels.

Microsoft confirms that it has investigated the issue fully so that the described issues won't occur anymore.

"To help us better detect issues like this, today we have enabled a new feature in the Windows Insider Feedback Hub", stated the blog post.

Microsoft made a decision to remove these duplicate folders through code incorporated into version 1809.

Microsoft discovered in its investigation that the issue impacted one one-hundredth of one percent of version 1809 installs. Other folders you can move include Desktop, Documents, Pictures, and Videos.

Correcting the issue required three specific fixes, each of which you can read about in more detail in Microsoft's blog post. "That change, combined with another change to the update construction sequence, resulted in the deletion of the original "old" folder locations and their content, leaving only the new "active" folder intact". The company also states it will provide an update as soon as a fixed version of the Windows 10 October 2018 will be rolled out again. However, it is holding back on releasing the new operating system generally until further testing is completed. You want to save some files separate from your primary folder, so you add another drive to your system for these.

Users who moved a Known Folder to OneDrive but did not move files in the process had files deleted in the old location.

Microsoft has also changed the workaround text on its website.

As for users that were affected, the firm says that "Microsoft Support is assisting customers and trying to recover data" and that this support can also be offered by the retail support services in-store.

Rather than immediately make the updated bits available to the public, Microsoft says it's limiting the initial release of this update to devices that are part of the Windows Insider Program.