If you reset your Windows device, you assume that all files from the previous installation will then be deleted. However, files can survive the reset. This is the case even if the users specifically chose “Erase everything” during the reset.
Privacy Issue: Resetting Windows doesn’t delete all files
This problem affects Windows devices with files that are on Onedrive or Onedrive for Business and have been downloaded or synchronized from there to the Windows computer. Such files can be found in the Windows. old” survive the reset.
However, the issue only affects files that have been opened or downloaded on the Windows device being wiped. Microsoft reports that files that are only stored online on OneDrive and not downloaded or synchronized locally are not affected.
These Windows versions are affected: The problem affects all current versions of Windows 10 and 11. According to Microsoft, the cumulative update KB5006670 from October 2021 causes this problem on Windows 10 systems. The update already has a bad reputation because it also caused printing problems. However, Microsoft did not reveal what causes this problem with the files surviving in “Windows.old” on Windows 11 machines.
Microsoft specialist Rudy Ooms discovered this problem. In addition, Ooms found that on some systems, data encrypted with Bitlocker is also moved to the Windows.old folder in unencrypted and readable form after a Windows reset.
Delete the “Windows.old” folder with the program and data remnants of an old Windows installation if you take over all its rights beforehand.
Microsoft Develops Patch: After this bug became known, Microsoft started working on a patch to fix the bug in an upcoming Windows update. At the time of going to press, however, the patch was not yet available.
Workaround: Until then, Windows users can avoid this issue by logging out of or unlinking Onedrive before resetting their Windows device.
Users affected by the problem should be able to use a function in the Windows settings to remove any remaining files on devices that have already been reset. This allows the folder “Windows.old” including private data to be deleted.
That’s how it’s done:
Under Windows 10, select “Windows icon -› Settings -› System -› Storage -› This PC -› Temporary files – ›Previous Windows installation(s) -› Remove files”. Under Windows 11, select “Windows icon -› Settings -› System -› Storage -› Clean up recommendations -› Temporary files – ›Previous Windows installation(s) -› Remove files”. You can also delete the “Windows.old” folder in Explorer, but you must first take over its system rights, which does not always work. If there is no “Windows. old” files are present, the “Previous Windows installation(s)” option does not appear.
Delete data on the SSD completely and securely