Those updates will occur every September and March, according to a Microsoft blog post by Bernardo Caldas, general manager of Windows commercial marketing.
The two-per-year rule and timing will also apply to the Office 365 application bundle—well, at least to the Office ProPlus version of the cloud applications suite. Office ProPlus, for Macintosh computers and Windows PCs, includes the usual Office applications—Word, Excel, PowerPoint, and Outlook—plus the Access database, Skype for Business for Internet calling, OneDrive cloud storage, and the OneNote note-taking app. Office ProPlus is often the version of Office that is included in large volume purchases of Microsoft products.
Apparently, the rest of several Office 365 versions will continue to be updated as needed. And there are several. The Office 365 site lists three plan options for home users, three for small businesses, four (including ProPlus) for "enterprises," two for schools; and five for non-profit institutions.
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Caldas said Microsoft (msft) was responding to user requests for more predictable releases with its new policy. Each update of Windows and Office 365 ProPlus will now be supported for 18 months, up from 12. Big customers, in particular, don't want to deal with lots of one-off updates and upgrades, even if those changes are accomplished online.
Windows System Center administration software, which big companies use to deploy and manage software, has also been updated to this new schedule.