Warning: Multiple Windows 10 retirements ahead

Two Windows 10 feature upgrades will reach end of support in the next seven weeks, the congestion caused by decisions Microsoft made earlier this year as the coronavirus pandemic began.

And a separate upgrade dropped off the support list last week, three years after its release.

Oct. 13: Windows 10 1709

A week ago, Windows 10 Enterprise 1709 and Windows 10 Education 1709, two SKUs that debuted in October 2017, received their final security updates.

At release, those SKUs were given 18 months of support. In early 2018, Microsoft gave them a six-month boost, extending support to 24 months. Several months later — in September 2018 — the Redmond, Wash. developer again changed Windows 10's support policies, giving them 30 months of security updates.

The final adjustment to Windows 10 Enterprise 1709 and Windows 10 Education 1709 was made in March, as the coronavirus triggered Microsoft's first retirement delay. "To ease one of the many burdens you are currently facing, and based on customer feedback, we have decided to delay the scheduled end of service date," a Microsoft executive said. The extension gave 1709 a total of almost 37 months of support, a record for Windows 10.

Windows 10 1709 easily won the dubious award for the highest number of alterations to its support lifecycle.

Nov. 10: Windows 10 1809

In three weeks, Microsoft will deliver the final security patches and non-security fixes for Windows 10 Home 1809 and Windows 10 Pro 1809.

Originally, those Windows 10 SKUs (stock-keeping units) were to exit support May 12, about 18 months after their Nov. 13, 2018 launch. But in April, just weeks after much of the US went into COVID-19 lockdown, Microsoft extended support until Nov. 10. "We have been evaluating the public health situation and understand the impact this is having on many of our customers," Microsoft said at the time. "To help ease some of the burdens customers are facing, we are going to delay the scheduled end of service date for ... version 1809 to November 10, 2020."

Windows 10 1809 was the first of several end-of-support postponements Microsoft implemented in 2020.

The extra six months of support allowed the company to serve Windows 10 Home 1809 and Windows 10 Pro 1809 with the newest replacement, Windows 10 2004, the feature upgrade that rolled out in late May, rather than November 2019's Windows 10 1909.

(Windows 10 Enterprise 1809's and Windows 10 Education 1809's end-of-support dates have not changed; they remained as May 11, 2021, thus providing 30 months of patches and bug fixes.)

What happened to 1803's November end of support?

Observant IT admins might wonder what happened to end of support for Windows 10 Enterprise 1803 and Windows 10 Education 1803? The two SKUs launched in April 2018 and so should have fallen off the list after 30 months, or in November 2020.

In August, Microsoft pushed those upgrades' end of support from Nov. 10, 2020, to May 11, 2021. The reason? Again, COVID-19.

"We have heard your feedback and understand your need to focus on business continuity in the midst of the global pandemic," Microsoft said at the time. "As a result, we have decided to delay the scheduled end-of-service date for the Enterprise, Education, and IoT Enterprise editions of Windows 10, version 1803."

The additional support will extend the total of Enterprise 1803 and Education 1803 to around 36 months, or three years.

Dec. 8: Windows 10 1903

This upgrade, which launched May 21, 2019, was allowed 18 months of support, and thus was set to retire Dec. 8, 2020.

That hasn't changed.

Microsoft didn't monkey with this one — not yet, anyway — and still expects all Windows 10 users, from Home and Pro to Enterprise and Education, to have moved on to something newer in the next seven weeks.

With the pandemic still disrupting business — many major US firms have said employees will work remotely until at least halfway through 2021 — it may seem odd that Microsoft hasn't extended 1903's support after doing so for the three prior upgrades. One possible reason: Microsoft believes IT staffs have adapted to the new abnormal and can now deploy upgrades to their scattered workforces without stretching deadlines.

There's always a chance Microsoft will grant Windows 10 1903 a late reprieve. A factor in favor of doing so: According to analytics vendor AdDuplex, a still-significant 26% of all Windows 10 devices were running 1903 at the end of September. That number was about half again as much as the later-delayed Windows 10 1809 accounted for at the same point prior to its original retirement date.