Microsoft's Windows 10 is scheduled to go on sale on July 29.
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
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