Cumulative fixes and monthly rollups come to the legacy operating systems.

In August, Microsoft announced that it was going to change the patching model used by Windows 7 and 8.1—as well as Windows Server 2008, 2008 R2, 2012, and 2012 R2—to something close to that of Windows 10.

In a break from Microsoft's older operating systems, Windows 10's monthly updates incorporate both security and non-security fixes into a single monolithic update. These updates combine not only each month's new fixes, but also the fixes from previous months. A similar system is being offered to those older operating systems. The patch on Oct. 11 is the first time this new system is being used.

The system for the legacy operating systems has complexities that Windows 10's patching lacks. There will be three series of updates in total. Two of these updates will be a monthly roll-up that combines security and non-security fixes, as well as a monthly security update that contains only that month's security fixes without any previous ones. They will be released on the second Tuesday of each month, known as "Patch Tuesday." The third update will be a preview of the next month—which combines the current month's cumulative update with the next month's non-security fixes—will be published on the third Tuesday of each month. This will give users the ability to test the non-security portions of each month's patch before it's rolled out.

The cumulative updates (both preview and regular) will be distributed through Windows Update, Windows Server Update Services (WSUS), and the Windows Update Catalog. The standalone security updates will only be available to WSUS and the catalog.

Starting in February 2017, Microsoft intends to add older fixes from before the current month to the packages. Over the course of several months, the cumulative updates will become bigger and bigger, incorporating an ever larger quantity of the available Windows 7 and Windows 8.1 fixes. The ultimate goal is that these cumulative updates will be sufficient to get a PC completely up-to-date. Eventually, this will mean that you'll no longer have to install hundreds of individual updates across multiple reboots to get a fresh install patched.

Microsoft's lengthy blog posts describe the various supported update strategies, and the company recommends users that install both cumulative updates as they're made available.

This change in policy i's going to cause ripples. Microsoft's rationale is sensible enough: the only configurations it actually tests are those with all patches installed. Accordingly, any organization that's installing individual hotfixes is using a system configuration that is untested and minimally supported. By bundling the updates together means, Microsoft ensures that the deployed update configuration will always match the tested one. But the major concern is that this bundling means that administrators won't be able to skip a buggy fix while still installing all the others.

Microsoft's answer is unlikely to make concerned administrators happy: admins should perform phased deployments across an organization and optionally join the company's "Security Update Validation Program." That program offers certain eligible companies early access to the security fixes.