Microsoft has acknowledged that a Windows 10 upgrade is losing security certificates under certain circumstances.

The issue was first reported by Borncity, when users started noticing problems after updating to the latest Windows 10 upgrade. According to the blog, “after installing cumulative October 2020 updates, various Windows 10 versions forget their certificates when upgrading to a higher Build.”

Microsoft has now acknowledged the issue exists when upgrading from Windows 10 version 1809 to a newer version.

System and user certificates might be lost when updating a device from Windows 10, version 1809 or later to a later version of Windows 10. Devices will only be impacted if they have already installed any Latest cumulative update (LCU) released September 16, 2020 or later and then proceed to update to a later version of Windows 10 from media or an installation source which does not have an LCU released October 13, 2020 or later integrated. This primarily happens when managed devices are updated using outdated bundles or media through an update management tool such as Windows Server Update Services (WSUS) or Microsoft Endpoint Configuration Manager. This might also happen when using outdated physical media or ISO images that do not have the latest updates integrated.

For impacted systems, Microsoft recommends using the uninstall window to roll back to a previous version of Windows using these instructions. Impacted users will then need to wait until a fix is released before upgrading again.