"I have just updated my windows using the October update (10, version 1809). It deleted all my files of 23 years in amount of 220GB. This is unbelievable, I have been using Microsoft products since 1995 and nothing like that ever happened to me," he wrote on Microsoft's user forum.
"Files were located at C:/Users/rober/Documents/. This location is still present, with no files. All files deleted."
Fortunately, he did back up his system two months ago and was able to restore those deleted files, but lost everything since that snapshot. Rolling back to an earlier build also did not restore the deleted files.
Separately, Microsoft has blocked the Windows 10 1809 update for some systems due to a compatibility problem with Intel Display Audio device drivers. The issue causes "excessive processor demand and reduced battery life" if the affected system is updated.
The compatibility problem affects systems with Intel Audio Display device driver, intcdaud.sys, versions 10.25.0.3 to 10.25.0.8.
Customers with affected Intel drivers will see a 'What needs your attention' warning message outlined in this support document for KB4465877.
Microsoft recommends selecting 'Back' rather than confirm, which keeps the system on the current version of Windows 10.
"To ensure a seamless experience, we are blocking devices from being offered Windows 10, version 1809 until updated Intel device drivers are installed on your current operating system," Microsoft notes.
The company is also advising users with the affected Intel drivers against manually updating to Windows 10 1809.
"We recommend that you do not attempt to manually update to Windows 10, version 1809 using the Update Now button or the Media Creation Tool from the Microsoft Software Download Center," said Microsoft.
"Wait until newer Intel device drivers are available with the update. This page will be updated when the block has been removed."
Intel has a fix available in the form of driver 10.25.0.10, which is bundled in the Intel Graphics Driver version 126.96.36.19986 and newer.
Intel said it "strongly recommends" users with its 6th Generation Skylake CPUs or newer processors to confirm they have the updated version before installing Windows 10 1809.
Microsoft will soon begin delivering the official release of Windows 10 version 1809, the October 2018 Update. If you do nothing, it will arrive via Windows Update some time in the next few months. Here's how to take more control over the process.