If Microsoft follows through on its announced plans for updating and upgrading Windows 10 after the new OS launches in two weeks, it will issue the first update no later than the end of November or early December, then follow with three more in 2016, repeating with a trio each year following.
Lather, rinse, repeat.
The update churn will result in a near-constant patter about upcoming updates and upgrades -- Microsoft itself isn't sure which of those terms apply, using both interchangeably -- for customers to digest.
Microsoft has left those customers guessing on answers to a slew of questions about Windows 10 refreshes, ranging from how long the updates and upgrades will appear free of charge to how substantial those changes will be. But it's talked about the schedule, pulling back the curtain in small jerks.
Here's what's known about the timetable and what's still unknown -- or in the infamous words of former Secretary of Defense Donald Rumsfeld, the "known unknowns" -- as the July 29 release date looms.
Updates will come every four months
According to a Microsoft-hosted webinar in late April, Windows 10 will receive updates about every four months, or three times a year.
It's likely that Microsoft won't hew to a set schedule, as does Mozilla, which rolls out a new edition of Firefox at almost-sacrosanct six-week intervals. Microsoft could trim the time between updates or extend the timeline, depending on whether it's satisfied with the quality and composition of the new build, or even on external factors, like the calendar.
If Microsoft wanted to present a newer Windows 10 for the end-of-year holiday sales season, for example, it would like to have that on new devices no later than mid-November, meaning a release -- or, at least, finished code -- in October.
Such flexibility is not guaranteed: We simply don't know because Microsoft won't say, or doesn't know itself.
But on average, expect to see updates/upgrades spaced out every four months.
The first update will appear before year's end
Four months from the July 29 launch date would be November 29, close to the start of winter in the northern hemisphere.
Although that date may not be set in stone, it's clear that to make good on its promises Microsoft must roll out a finished first update/upgrade before year's end.
That alone will be a record for the company: The previous shortest lag has been the six months between Windows 8.1 (launched Oct. 17, 2013) and Windows 8.1 Update (April 8, 2014).
Consumers as guinea pigs get the first update
The first update/upgrade will be primarily, perhaps exclusively, for consumers, delivered to devices running Windows 10 Home by default via the Windows Update service. Microsoft is calling that update cadence or track "Current Branch" (CB), part of the new release lexicon the Redmond, Wash. company's invented.
Those running the more advanced Windows 10 Pro can also adopt the consumer-speed CB track. People most likely to do so are the power users, enthusiasts and work-at-homers with a Pro edition, as companies -- which also widely deploy the various Windows' Professional or Pro SKUs (stock-keeping units) -- will probably play it conservative and instead take updates from the Current Branch for Business (CBB) after they have moved to Windows 10 Pro.
Not everyone on CB will get the first update at the same time
Microsoft has provided some update flexibility (its take) or complicated matters (the cynic's view) by segmenting each "branch" into "rings." The latter is a second release timing mechanism that lets customers receive a branch's update as soon as the build is approved via a "fast" ring, or delay the update's arrival using a "slow" ring.
Rings on the CB were confirmed only this week by Terry Myerson, chief of the company's OS and devices division, and may number more than the two: Again, Microsoft's not elaborated.
Nor has it said how long the stretch will be between fast and slow. It may be weeks; it could be months.
The Windows Insider preview program, which will continue to run after July 29, has put devices into the slow ring by default; Microsoft may or may not do the same with the CB.
The one certainty is that not everyone on the CB will get the update immediately. "Some consumers just want to go first. And we have consumers that say, 'I'm okay not being first,'" Myerson said on Monday.
Most business PCs won't get the first update until the Spring of 2016
Because Microsoft will be using its Insider participants, and more importantly the millions of consumers running Windows 10, as testers, it will not release builds to businesses at the same time as those on the Current Branch.
With the four-month stretch between updates/upgrades and the automatic delay built into the Current Branch for Business (CBB), customers on the latter will not receive the first build until next year: On a strict schedule, that will be at the end of March or beginning of April 2016.
Microsoft's doing it this way, it's said, to produce more bug-free code to its most important users, businesses. Microsoft figures that the four months will shake out more bugs so that those running Windows 10 Pro or Windows 10 Enterprise will get a more stable update with a correspondingly lower risk of something breaking.
Users of Windows 10 Pro and Windows 10 Enterprise can stick with the old way of managing updates -- using Windows Server Update Services (WSUS) or another patch-management product -- or go with the new Windows Update for Business (WUB), an analog to the consumer-ish Windows Update service.
Those on WUB must deploy a given build within four months of its release or Microsoft will shut off the patch spigot: That means CBB users applying updates/upgrades with WUB must have the first build on their devices by approximately Aug. 1, 2016.
Businesses can delay the first update only so long
Microsoft's not giving anyone a choice: Either take the updates and upgrades or face a security patch drought. (The one exception: Windows 10 Enterprise.)
The longest delay allowed for CBB will be eight months from a specific build's release to the branch, or 12 months after the same build has hit the consumers via the CB.
Customers using WSUS or another Microsoft (or third-party) patch management solution must have the first build deployed no later than late November, early December 2016.
Businesses get rings, too
The CBB will offer users release "rings" as well, at the very least a slow ring and a fast ring, but there may be others.
Microsoft has talked about rings on the CBB since the May announcement of Windows Update for Business, but as with rings on the CB, details remain muddled. How long the slow ring follows the fast, for instance, is unclear.
Only Windows 10 Enterprise can ignore the updates and upgrades
The only Windows 10 edition that can pass on the constant updates and upgrades is Enterprise, the SKU available solely to organizations that have a volume licensing agreement tied to the annuity-like Software Assurance (SA) program.
The branch available only to Windows 10 Enterprise, dubbed Long-term Servicing Branch, or LSTB, mimics the traditional way Microsoft has handled its OS: Only security patches and critical bug-fixes will reach systems on the LTSB.
Every two to three years, Microsoft will create another LTSB build, integrating some or all of the feature changes released to CB and CBB in the intervening time, then offer that to customers. They will have the option to move to that build -- it won't be mandatory -- and can skip at least one build, passing on LTSB 2 (or whatever Microsoft names it), then years later adopting LSTB 3 with an in-place upgrade.
The code released on July 29 will be considered LTSB 1, Microsoft has said, so a second, optional LTSB won't appear until 2017 at the earliest.
By December 2016, there will be multiple update/upgrade builds being used
The staggered releases Microsoft plans will create a situation where multiple builds are in use at any one time, each by a segment of the Windows 10 device population.
Come December 2016, Microsoft will have issued its fourth build to the CB, and the third to the CBB. But there will be some still using the second build (those on the CBB managing updates with WSUS).
Analysts, however, have largely discounted fragmentation as a factor, arguing that while the delays offered to businesses on the CBB may be disruptive, Windows 10 will ultimately be a more uniform ecosystem than the current mix of vastly different editions of Windows.
What Microsoft gets out of this stretched, staggered release schedule
Microsoft may pitch the Windows 10 update and upgrade schedule as all about customers, but there's something in it for the company, too.
"Rings will be more about controlling the rate at which the updates flood out into market," said Steve Kleynhans, an analyst at Gartner, in a recent interview. "With potentially a billion devices ... eventually ... getting an update, you need some level of flow control or else you could crush your servers and a large part of the Internet. By using rings, Microsoft can stagger the release over the period of days or weeks."
In fact, the entire cadence, not just the rings, can be envisioned as Microsoft's way of reducing stress on its update servers. Although the second build for the CB -- slated for late March-early April 2016 -- will coincide with the launch of the first build for the CBB on Computerworld's timeline, it will not be a surprise if Microsoft staggers the two by launching first one, then the other.
Microsoft is clearly concerned about server load and the possibility that something could go awry: It's not releasing the free Windows 10 upgrade to all eligible customers on July 29. Instead, it plans to give the several million Insiders the code first, then gradually trigger upgrades on others' devices in an unknown number of "waves" that could run weeks or months.
The company will also control demand for the upgrade another way by silently downloading the bits in the background to eligible PCs and tablets, then notifying them on its own schedule that the upgrade is ready to process locally.
It may do the same with later updates and upgrades, Kleynhans speculated.
"I wouldn't be surprised if under the covers Microsoft uses a separate ring for each week after an OS is released, or maybe even one for each day immediately after it is out," said Kleynhans. "But these will be mostly invisible to users and really isn't all the different from the way some updates roll-out today."
The naming problem
Computerworld has used generic place holders to identify the various update/upgrade releases Microsoft will distribute to Windows 10 -- "first build" and "LTSB 2," for instance -- because Microsoft hasn't talked about how it's going to name each build.
That will have to change.
"Another factor that Microsoft has yet to discuss is how it will identify each update," Kleynhans said. "We know that the OS will be called Windows 10 regardless of what updates have been delivered and installed.... But as for identifying the state after each update, we don't know if Microsoft will stick with the build number, as it has during the preview program, opt for a simplified numbering scheme -- something similar to the build number but without the holes in the numbering scheme -- go back to point identifiers [like] Window 10 v 10.1 and Windows 10 v 10.2, [as] Apple does with OS X, or maybe use something more date oriented [such as] 'Windows 10, July 2016.' There will have to be something to help developers understand what they are facing in the field."