In March, Microsoft officials said they were temporarily halting the release of optional Windows 10 cumulative updates that they had been making available in the third and fourth weeks of each month due to the impact on customers from the COVID-19 coronavirus pandemic. On June 17, Microsoft officials said they are planning to resume these optional releases in July 2020 for Windows 10 and Windows Server 1809 and later.
Before March, Microsoft had been releasing updates and patches to Windows client and server almost every week. The first week of each month (A week) is typically for Office updates. B week is the second week of the month and when Patch Tuesday is -- "Update Tuesday" in Microsoft's euphemistic parlance. C and D weeks, which are the third and fourth weeks of the month, or when Microsoft releases optional cumulative updates that are intended to be previews of non-security fixes for IT pros and admins. These optional updates are not installed automatically.
Microsoft's new plan for rolling out non-security monthly updates (previously known as "C" and "D" week releases") will be slightly different from before.
Microsoft will be calling these optional releases "Preview" releases, going forward. They will be making them only available to a subset of users -- those on Windows 10 and Windows Server 1809 and later. And in the name of simplifying update management for IT, these Preview releases will be delivered in the "C" week, or the third week of each month, only. Cumulative security updates will continue to be delivered in the "B" week on Patch Tuesday.
Any IT pros using Windows Server Update Services (WSUS) to manage updates will no longer see Preview or "C" releases for Windows 10 or Windows Server in the WSUS channel, officials said today. And those in the Windows Insider and/or Windows Insider Program for Business will see the "in-development" versions of these optional cumulative updates made available in the Release Preview Channel during "B" week, Microsoft's blog post said.