Microsoft has issued Windows 10 21H1, officially the year's first feature upgrade even though new functionality was largely absent because Redmond has abandoned its major-minor release cadence.
Only customers throwing caution to the wind as early adopters can immediately upgrade to 21H1, and then only if their computers meet Microsoft's unspoken criteria. Alternately, IT administrators can deal out the refresh to workers' devices using their preferred management tools.
"We are initially taking a measured seeker-based approach to the rollout of the May 2021 Update," wrote John Cable, the Microsoft executive who leads the Windows servicing group, in a May 18 post to a company blog.
On PCs running Windows 10 Home and on those Windows 10 Pro machines not managed by IT, 21H1 will be installed only when the user chooses the "Download and install now" option. As Cable noted, of the eligible PCs — those running one of the last two versions, either 20H1 (also labeled 2004 at the time) or 20H2 — only a portion will be offered this week's upgrade at the start. Microsoft has long used a scheme that only slowly expands the pool of potential recipients and will continue that practice this time.
"We are throttling availability up over the coming weeks to ensure a reliable download experience for all, so the update may not be offered to you right away," Cable said.
In many cases, Microsoft will refuse to offer Windows 10 21H1 because the target machine has been tagged with an incompatibility of some kind. Often, those are linked to specific hardware configurations or problematic software. The vendor details these so-called "stoppers" — though Microsoft refers to them as "safeguard holds" — on its Windows release health website.
Enterprise: To the testing lab, stat!
Two months ago, Microsoft urged commercial customers to begin testing Windows 10 21H1 using a release candidate of the upgrade.
Microsoft also told IT admins to start what it called "targeted deployments," meaning small-scale rollouts to PCs whose users have previously been identified as each upgrade's guinea pigs. "We recommend that commercial organisations begin targeted deployments to validate that their apps, devices and infrastructure work as expected with the new release." Cable said, using the company's boilerplate language.
The upgrade was immediately available through Windows Server Update Services (WSUS), including Microsoft Endpoint Configuration Manager; Windows Update for Business (WUfB); the Volume Licensing Service Center (VLSC); and Microsoft's download centre via the Update Assistant and Media Creation Tool.
Minor, minor ... where's the major?
Windows 10 21H1 represents a hitch in Microsoft's release cadence. Like last fall's Windows 10 20H2, this year's 21H1 is as much a feature upgrade as a backyard swing set is Disneyland.
Microsoft ditched the major-minor tempo of 2019 and 2020 — major release in the first half of each year, minor in the second half — for this refresh, the second straight minor. Rather than an upgrade composed of numerous new features and functionality, the minor 21H1 combined the code of its immediate predecessor (that would be 20H2, which reused its predecessor's code) with the intervening fixes, then added a splash, a very small splash, of shiny new things.
Because 21H1 is little more than a repeat of 20H2, the code for the latest cumulative update of the latter is identical to the code for the former.
Windows 10 20H2-to-Windows 10 21H2 upgrades, then, are finished faster than the usual wholesale OS replacements customers have been accustomed to for decades. That alone has been a big boon to business IT personnel, and one of the reasons why the minor instance have been welcomed like they have.
But it begs the question: Will the fall upgrade be another minor, as the 2019-2020 pattern would suggest? Put a different way, will Microsoft offer a legitimate upgrade, rather than a rehash, in the second half of 2021? Or ever? Microsoft's not saying, as is usual for the closed-mouthed company.
All that's necessary to turn 20H2 (or because of the special circumstances, even 2004) into 21H1, then, is a tiny download that switches on the little bits that are new in the 21H1. Microsoft calls that download an "enablement package."
Microsoft embedded 21H1's differences inside the May cumulative update for 20H2 and 2004, the one released May 11, so as long as that has been deployed, customers are good to go with the entitlement.
Windows 10 21H1 will receive the now-standard minimum support of 18 months, putting its retirement date as 13 December 2022. As it is a first-half upgrade, all editions of the OS, including the priciest and most comprehensive, Windows 10 Enterprise, receive the same amount of support for 21H1.