Windows 10 update (and retirement) calendar: Mark these dates

Windows 10 was supposed to release, rinse and repeat on a metronomic cadence. Ticktock. Each update was to have its months in the sun, then fade away as its support expired. Ticktock. The repetitive, predictable schedule was to revolutionize operating system progress by replacing the every-several-years upgrade jolt.

Ticktock.

That promise, though, got misplaced as Microsoft rearranged and rejiggered Windows 10's support and update practices.

This year, Microsoft messed with the nomenclature of the still-twice-annual upgrades, dropping the yy03 and yy09 labels for the vaguer yyH1 and yyH2, an admission that the supposed precision of the earlier tags fooled no one. With half a year – first or second – as a target, Microsoft gave itself the wiggle room the original plan had rejected as old-fashioned, if not obsolete.

And as expected, Microsoft will reprise the 2019 major-minor release practice this year. For all its talk of "monitoring feedback" and "hoping to learn" whether to repeat the delivery of one major refresh and one very minor retread, or return to a pair of equal upgrades, Microsoft didn't seem to hesitate when picking the former – not during an upside-down, inside-out year of the novel coronavirus.

Each year of Windows 10 witnesses new decay of the original concept. Each mutation of the plan comes as a surprise to customers.

That's why everyone should be marking the calendar with Windows' most important release events. This is the latest schedule; pencil in these dates.

April 13, 2021

Windows 10 21H1 — probably nicknamed "April 2021 Update" — may release after this date, the month's Patch Tuesday. (Remember, Microsoft changed its feature upgrade naming convention in June 2020, dropping the yymm format for the new yyH1 and yyH2 for each year's first- and second-half releases.)

It is possible that Microsoft will not issue a spring feature upgrade (as it's done since 2017); reports have circulated that the firm will shift to a once-a-year tempo by giving the first slot of 2021 to the launch of Windows 10X, another attempt by the company to craft a lighter-weight OS to compete with the likes of Google's Chrome OS and Apple's iPadOS.

If Windows 10 21H1 does appear, it will be installed primarily by Windows 10 Home and Windows 10 Pro customers because of its shorter 18-month support lifecycle.

Gregg Keizer/IDG

Feb. 3, 2021

On this date, Microsoft told commercial customers that Windows 10 2004 was reliable and stable enough that it could be deployed to all corporate PCs. "Windows 10, version 2004 is designated for broad deployment," Microsoft said.

That guidance was notable — not for its appearance, for Microsoft has consistently declared Windows 10 versions' suitability for broad rollout — but because it came more than eight months after the May 27, 2020, launch of Windows 10 2004.

The delay was the longest yet for Microsoft, breaking the prior record of six and a half months set by Windows 10 1909, 2004's immediate predecessor. Previously, the time gap between launch and a Microsoft declaration was shorter, on the order of four months as an average.

So, why did it take nearly half the 18-month support lifetime of Windows 10 2004 to declare it safe and sound? And more importantly, are these notifications still valuable to IT administrators?

Computerworld doesn't have definitive answers for the first two questions. On the third, our take is that, no, they're not. Not with delays so lengthy that the messages become meaningless, so tardy that months of active use were wasted. 

Computerworld will, for now, continue to insert its projected dates for Microsoft's ready-for-business into this calendar, using a seven-month lag between release and notice, a rough average of the last two notifications.

Frankly, IT admins would be better served to use their own judgment, not Redmond's, as to when to push a larger deployment.

May 11, 2021

Microsoft serves the last security patches and other bug fixes to Windows 10 Home 1909, Windows 10 Pro 1909 and Windows 10 Pro Workstation 1909, wrapping up 18 months of support.

IDG/Gregg Keizer

May 11, 2021 ... Take #2

Microsoft delivers the final updates for Windows 10 Enterprise 1809 and Windows 10 Education 1809, ending 30 months of support for the fall feature upgrade.

Customers running 1809 must migrate to a newer refresh – 1903, 1909, 20H1, 20H2 or even the possibly-just launched 21H1 – to continue to receive security patches. Windows 10 Enterprise 20H2 and Windows 10 Education 20H2 would seem to be the best bet, since they have the most support remaining (about 24 months from this date).

May 18, 2021

Somewhere around this date, Microsoft should inform IT admins that Windows 10 20H2 — the service pack issued seven months ago on Oct. 20, 2020 — is ready to deploy throughout their organizations. This message may appear on the Windows Update Twitter account and/or on the Windows release health hub.

Aug. 17, 2021

If these were normal times, Microsoft would begin to upgrade Windows 10 Home and Windows 10 Pro PCs running version 2004 with Windows 10 21H1 around this date.

But what if 21H1 doesn't exist? (See "April 1, 2021" for details.)

Gregg Keizer/IDG

Computerworld scoped out how Microsoft might deal with the no-show of Windows 10 21H1 (to make room for an introduction of Windows 10X) in that story's "No spring, forward to fall" section. There's no need to walk that ground again.

Suffice it to say that one way Microsoft could handle the problem would be to upgrade Windows 10 2004 with version 20H2, a one-time stutter step to prep for a switch to upgrading in the fall, not the spring, each year. Computerworld laid out how Microsoft might do that, theorizing that the developer would warn users of Windows 10 2004 early this year of the change. It hasn't.

As always, only Microsoft knows what it will do. Or so we assume.

Aug. 17, 2021 ... Take #2

Microsoft may alert enterprise customers around this time that Windows 10 21H2 is available for "commercial pre-release validation."

That is, if 21H1 was released in the spring.

In 2020, two months before launching Windows 10 20H2, Microsoft said the upgrade was "available for commercial customers to begin feature exploration and validation prior to being released for general availability."

The early look at 20H2 was possible, of course, because the fall feature upgrade was little more than a rehash of the spring's Windows 10 2004. (Microsoft switched its labeling between the two, discarding the yymm construction for yyH1 and yyH2. Yes, Microsoft's nomenclature tinkering is endless....) The changes embedded in 20H2 were both few and minor, and importantly, were tucked into the Windows 10 2004 code weeks before 20H2 officially went live on Oct. 20, 2020.

Microsoft's urging of customers to start putting Windows 10 20H2 through the testing wringer was explicit in 2020. The year before, when Microsoft first turned to a major-minor upgrade cycle, it had left this early jump to customers' (and Computerworld's) imaginations. If the company does repeat 2019's and 2020's release practice, Computerworld believes it will formalize this practice, and again tell corporate customer to start testing two months before public launch.

Oct. 1, 2021

Microsoft begins rolling out Windows 10 21H2, aka "October 2021 Update," after this date. The probable launch: Patch Tuesday, Oct. 12.

The 30-month support lifecycle on Windows 10 Enterprise and Windows 10 Education means this will be the year's preferred upgrade for Microsoft's larger customers. The Redmond, Wash. developer will service this version until April 2024.

Oct. 12, 2021

"Mainstream" support ends for Windows 10 Enterprise 2016 LTSB, the second no-changes-allowed build that Microsoft offered for deployment in instances unsuited to the Windows-as-a-service model.

LTSB, for "Long-term Servicing Branch," which was later rebranded as LTSC (Long-Term Servicing Channel), is the only edition of Windows 10 which retained the traditional 5+5 support scheme of Mainstream and Extended periods.

This date ends some support, including feature change requests and non-security bug fixes. For a more detailed description of Mainstream and Extended, refer to this document.

(Note: This milestone of 2016 LTSB does not end support of 2015 LTSB, Microsoft's first static build. Windows 10 Enterprise 2015 LTSB will continue in Extended support until Oct. 14, 2025.)

Nov. 9, 2021

Around this date, Microsoft ships Windows 10 Enterprise LTSC 2022 (Long-term Servicing Channel). The successor to LTSC 2019, which launched three years prior, this build will be supported until January 2032.

In a May 2019 blog post, a Microsoft marketing manager announced that customers could expect the next LTSC "toward the end of 2021."

Nov. 9, 2021 ... Take #2

If Microsoft released a Windows 10 21H1 earlier this year, around this date it may instruct corporate customers that the feature upgrade should be pushed into broad deployment. Microsoft will divulge this declaration on the Windows Update Twitter account and/or on the Windows release health hub.

Note: With almost half of the upgrade's 18 months of support already spent, the notice may be worthless to IT administrators.  

Dec. 14, 2021

Microsoft issues the final bug fixes and non-security changes to all SKUs (stock-keeping units) of Windows 10 2004, from Home to Enterprise, ending 18 months of support.

Gregg Keizer/IDG

Jan. 18, 2022

Microsoft kicks off forced upgrades that replace Windows 10 Home 20H2 and Windows 10 Pro 20H2 with the year-later refresh Windows 10 21H2.

Windows 10 Home/Pro/Pro Workstation 20H2 run out of support May 10, 2022, giving Microsoft 16 weeks to push the latest code to those PCs.

April 12, 2022

Windows 10 22H1 may release around this date if Microsoft decides to keep its twice-annual release tempo. (See the "April 13, 2021" section for the first instance when a spring feature upgrade may be omitted.) If it does not deliver 22H1, Microsoft may use the slot to upgrade Windows 10X.

Windows 10 22H1, if it exists, would exhaust its support in October 2023.

May 10, 2022

Support ends here for Windows 10 Enterprise 1909 and Windows 10 Education 1909, the upgrades that debuted in November 2019, concluding 30 months of security and non-security updates. (Windows 10 Home 1909 and Windows 10 Pro 1909 exhausted their support a year ago.)

The most suitable replacement will be Windows 10 21H2, the refresh released in October 2021 that also offered two-and-a-half years of support.

May 10, 2022 ... Take #2

Microsoft delivers the final security patches and bug fixes to Windows 10 Home 20H2, Windows 10 Pro 20H2 and Windows 10 Pro Workstation 20H2 — all launched Oct. 20, 2020 — and ending 19 months of support.