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.