With Windows Update for Business, an organization can take advantage of cloud-delivered updates, while still creating and managing a ring-based deployment approach. Using Windows Update for Business deferrals, you can group devices into deployment rings to control and manage the deployment of both monthly quality updates and semi-annual feature updates.
If devices under your management are still running Windows 10 Pro or Windows 10 Pro for Workstations, version 1709, your devices will reach end of service on April 9, 2019 if you have configured both of the following Windows Update for Business policies:
Branch readiness is configured as Semi-Annual Channel (SAC)
Feature update deferral is configured as 274 days or more
In order avoid this, you need to set your feature update deferral policy to 273 days or less.
To calculate the maximum number of deferral days you can configure and remain in service, determine the number of days between the release date of the next version your devices are moving to and the end of service date for your current version. In the case of Windows 10, version 1709, there are 273 days between the release date for Windows 10, version 1803 (July 10, 2018) and the end of service date for Windows 10, version 1709 (April 9, 2019).
How deferral policies work in Windows Update for Business
A feature update deferral is enforced at the time a device checks Windows Update for updates. If the configured number of deferral days has passed, the applicable update—which will have been in service for the number of configured deferral days—is offered.
Currently, the end of service date is not considered when evaluating a feature update deferral in Windows Update for Business. This, combined with the ability to delay the targeted phase of your deployment by setting branch readiness to SAC, makes it possible to defer past the end of service date for the currently installed release. After talking with customers and evaluating data on how deferrals are used across a broad set of organizations and devices, we do not believe that organizations using deferrals intend for their devices to reach end of service as those devices would no longer receive monthly security and quality updates.
For devices with branch readiness set to SAC, we recommend a feature update deferral be configured to no more than 180 days, which would ensure that devices under your management will always be in service. In the future, we will make changes to Windows Update for Business to safeguard against the condition where an extended deferral can result in devices reaching end of service.
With Windows 10, version 1903 and later releases, we have simplified the configuration as I explained in my previous blog post, which will also prevent a device from reaching end of service due to a deferral policy.