Microsoft Warns of Major Windows Update Bug

John Lister's picture

Microsoft has warned users not to install the latest major update by anything other than the automated process. Methods such as downloading the update onto USB drives or DVDs could cause significant problems thanks to a bug.

The issue affects the Windows 10 October 2020 Update, also known as 20H2 (version 2009, and build 19042). This is officially the second major update this year. It's currently available automatically through Windows Update, though is being gradually released to different people at different times rather than sent out to everyone at once.

Officially that's to avoid overwhelming Microsoft's servers. Unofficially, it gives Microsoft a chance to catch any bugs that weren't picked up in the testing process and are only revealed once a more general audience gets the update. This could mean a fix or pause on updates before the problems affect the entire Windows 10 user base.

Manual Installation A Risk

Often people who weren't in the testing program will try to jump the gun in situations like this by manually installing the update. This is also the case with those who have automatic updates switched off in favor of picking and choosing what to install but want to get the major twice-yearly updates in place as soon as they are ready. (Source:

Microsoft says it's now investigating a problem that can affect anyone whose machine has at least one small update released after September 16 this year and then tries to install the 20H2 update "via an alternative installation source or media." (Source:

This could include downloading the update and installing it from a USB drive or DVD (including burning an ISO file) or using update management tools other than the one built into Windows.

Drivers May Fail

The bug means that system and user certificates could disappear from the computer. Software and device drivers may also stop working as expected.

Microsoft says it's working on a fix for the bug and will patch the updates as soon as possible. In the meantime, anyone affected by the problem should roll back to a previous update by navigating to Settings > Update & Security > Windows Update > View your update history > Uninstall updates.

What's Your Opinion?

Do you use the automated Windows Update or manually control updates? Have you already had the 20H2 update? Have you encountered any problems since it came out?

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Draq's picture

I don't use anything to manage updates other than Windows Update itself, but have no issues that I know of. The only oddity that I've noticed is that the latest optional cumulative update preview for 20h2 is showing download and install on the main update area and not in the optional updates area.

Autodoof's picture

I installed 20H2 unknowingly (thinking it was 2004) through the in place upgrade method which involves using the Windows Media Tool directly in the C:\ drive. No difficulties were encountered then or later.

ghostwriter's picture

I installed the update on 10/28/2020. OS build 19082.572 Windows Feature Experience Pack 120.2212.31.0.

Haven't had any problems yet. In fact this update has gone smoother than any other. The next major update MS should give us should be on October 2025.