With this year's two Windows 10 feature updates, Microsoft has been more cautious than before, delivering new versions to small batches of users. Some still haven't seen the Windows 10 version 2004, publicly released in May, made available to them via Windows Update. This means that more users are now trying to skip the Windows Update process and get the new version through ISO files.

However, it turns out that may not be the best route to get the latest Windows 10 October 2020 Update - at least not at the moment. Microsoft has updated the list of known issues affecting latest version 20H2 with a new problem.

Titled as "Certificates may not be present after updating to a newer version of Windows 10," the Windows maker explains that if a user upgrades to a new version using ISO files, "system and user certificates might be lost." This doesn't happen to everyone, as the problem affects devices that haveinstalled cumulativeupdates "released September 16, 2020 or later andthen proceed to update to a later version of Windows 10 frommedia or aninstallation sourcewhichdoes nothave an LCU releasedOctober 13, 2020 or later."

Affected Windows 10 versions include:

Windows 10, version 20H2Windows 10, version 2004Windows 10, version 1909Windows 10, version 1903Windows Server, version 20H2; Windows Server, version 2004; Windows Server, version 1909; Windows Server, version 1903

Microsoft said it's working on a fix and promises to provideupdated bundles and refreshed media in the coming weeks. The company has suggested users who are already facing this issue to roll back to their previous versions.

Complete error report of this latest Windows 10 20H2 issue

System and user certificates might be lost when updating a devicefromWindows 10, version 1809 or laterto a later version of Windows 10.Devices will onlybe impactedif they have alreadyinstalledanyLatest cumulativeupdate(LCU)released September 16, 2020 or later andthen proceed to update to a later version of Windows 10 frommedia or aninstallation sourcewhichdoes nothave an LCU releasedOctober 13, 2020or laterintegrated. Thisprimarily happens whenmanaged devicesare updatedusing outdated bundles or media through an update management tool such as Windows Server Update Services (WSUS)orMicrosoft Endpoint Configuration Manager.This might also happen when using outdated physical media or ISO images that do not have the latest updates integrated.

Note  Devices using Windows Update for Business or that connect directly to Windows Updateare not impacted.Any device connecting to Windows Updateshould always receive the latest versions ofthe feature update, including the latestLCU,without any extra steps.

Workaround:  If you have already encountered this issue on your device, you canmitigate itwithinthe uninstall windowbygoingback to your previous version of Windows using the instructionshere.Theuninstallwindow might be 10 or 30 days depending onthe configuration ofyour environmentand the version you’reupdating to.You will then need to update to the later version of Windows 10 after the issue is resolved in your environment.NoteWithinthe uninstall window,you can increase the number of days you have to go back to your previous version of Windows 10 by using the DISM command/Set-OSUninstallWindow.You must make this changebeforethe defaultuninstallwindow has lapsed.Formore information,seeDISMoperating system uninstall command-line options.

- Relevant:W10 KB4580364 Is Available for v2004 and the October 2020 Update