Microsoft's latest Windows 10 feature update is now available to the public. Should you install the update, or should you wait? What happens if you wait too long? And why did the options to defer updates disappear from Windows 10 Settings?
Those are all good questions without easy answers.
The rules and tools for controlling these big feature updates used to be fairly simple. That's no longer true; unfortunately the formula for feature updates now feels more like a midterm exam in differential calculus.
When will Microsoft offer you a new feature update? When should you install that update? Before you can solve either problem, you need to calculate several variables. Let's go through the list.
This is the most important variable of all.
As it has since the dawn of the Windows 10 era, Microsoft reserves its full set of update management features for business editions. And in a relatively new wrinkle, the end-of-service date (the date when Microsoft stops supplying updates for a version) has a major impact on when feature updates are automatically installed.
To check which edition is running on the current system, click Start, type settings:about in the search box, and press Enter. That opens the Settings > System > About page, where you'll find your Windows edition and version information under the Windows Specifications heading. Make a note of that version information; you'll need it in the next section.
In the "Windows as a Service" era, Microsoft releases a new version of Windows 10 every six months. For all updates through the first half of 2020, the major version, corresponding to each one of those semi-annual feature updates, was expressed as a four-digit number in the format yymm. That number indicates the year and month in which the current version was finalized. Version 1909, for example, was completed in September 2019.
Beginning in the second half of 2020, that numbering system changes slightly. The yy portion remains, identifying the year in which the update was released, but it's followed by H1 or H2, indicating whether the release is from the first or second half of the year. The October 2020 Update, version 20H2, is the first to use this nomenclature, with 21H1 and 21H2 on deck for next year.
The version number is important because it allows you to look up the end-of-service date using the table on the Windows 10 Release Information dashboard. Here are the dates that matter right now:
Microsoft's policy is to begin automatically updating PCs running versions that are nearing their end of support date to the new version. The company has not supplied any details about how it will determine which devices get updated except to say that it uses a "machine learning (ML)-based rollout process several months in advance of the end of service date."
Enterprise and Education editions use a different servicing schedule, with support for some versions lasting 30 months instead of 18. Because of these longer servicing periods, versions as old as 1703 are still supported with updates. Administrators can use Windows Update for Business and Group Policy to defer feature updates for up to 365 days; to defer feature updates longer than that, you'll need enterprise management tools like Windows Server Update Services.
Ha! This one's a trick question. As of version 1903, mainstream versions of Windows 10 have one and only one servicing channel, called the Semi-Annual Channel. That change was announced in February 2019 in a post on the Windows IT Pro Blog: "Windows Update for Business and the retirement of SAC-T."
Previously, Windows 10 was delivered in two phases, one for consumers and small businesses and the second, a few months later, for wide deployment by businesses. In the beginning, these two phases were called the Current Branch and the Current Branch for Business. Those names were later changed to the confusing Semi-Annual Channel (Targeted), followed by the Semi-Annual Channel.
If you used Windows Update for Business to assign a machine to the second branch/channel and you assigned deferral dates to those updates, the deferral period didn't begin until Microsoft declared a release ready for widespread deployment by businesses.
That setting is no longer available as of version 1903. On PCs running earlier versions, Microsoft automatically added 60 days to the deferral period for devices that were assigned to the Semi-Annual Channel. But that was a one-time exception that expires on November 10, 2020, when the end-of-service date arrives for version 1809.
On a PC running Windows 10 Home or Pro, version 1903 or earlier, a new feature update will arrive sometime soon (maybe even today!). You might be able to delay its installation by a few days, but that's it.
If you're currently running version 1909, any edition, Windows will offer the latest feature update if you go to Settings and manually check for updates. But it won't install automatically, and you are free to ignore its entry in Windows Update.
On a PC running the Enterprise or Education editions of Windows 10 version 1803 or 1809, you can relax. The end-of-service date for those versions is May 11, 2021. But if you are running Windows 10 Enterprise/Education version 1903, you'd, uh, better get to work. Support for that version ends in just a few weeks, on December 8, 2020.
Now you see them, now you don't.
Shortly after the initial release of Windows 10, Microsoft added Group Policy settings to Windows 10, allowing administrators to defer updates to Windows 10. A year later, they added switches to the Windows Update pages in Settings, to make the process of deferring updates easier.
And then, in version 2004, those easy options disappeared. The official explanation from Microsoft is that the result of those settings was too confusing. But the upshot is that the only way to defer updates on currently supported Windows 10 versions is, once again, to use Group Policy settings. I have all the details in "Windows 10 update: The complete guide for businesses of every size."
Well, that's the billion-dollar question, isn't it?
Microsoft has made major revisions to its update policies for enterprise customers, and the company is being characteristically opaque with the details of those policies, scattering clues throughout various blog posts. After meditating deeply on those blog posts and then engaging in several rounds of Q&A with Microsoft managers responsible for those policies, I think I finally have it figured out.
The big takeaway is that end-of-service dates trump deferral policies. If you configure PCs in your organization for the maximum deferral period of 365 days, you run the very real risk that those devices will reach end of service before the deferral period ends.
Under some circumstances, PCs that are configured for the Semi-Annual Channel with a deferral period of 365 days for feature updatescould reach the end-of-service date (and be forcibly updated) months before the deferral period ended.
In an obscure recent blog post, Microsoft has acknowledged that this is an issue for administrators to be concerned about:
For devices with branch readiness set to SAC, we recommend a feature update deferral be configured to no more than 180 days, which would ensure that devices under your management will always be in service. In the future, we will make changes to Windows Update for Business to safeguard against the condition where an extended deferral can result in devices reaching end of service.
Of course, that's not a problem for administrators who've standardized on the Enterprise or Education editions of Windows 10 and who have deployed the H2 (second half of the year) releases. Because those releases have a 30-month servicing lifecycle, admins can safely defer updates for up to two years.
What's maddening about all these changes is that there's no central hub of information accessible from an easy to find link. If you're too busy to read every post on the Windows IT Pro Blog, you probably missed the flashing red signals that a change in update policy is afoot.
And, of course, there's absolutely no way to determine when Microsoft's update servers will target your specific device. All you know is that once the deferral period has ended or the end-of-service date is near, you're at risk of receiving a feature update when you least expect it.