From the Dark Side--Windows 11 26H2 is a 174KB Switch, and Microsoft Sets October 13 as the End of Updates for 24H2 Home and Pro

2026October 9, 2026Macs Only!Dark Side
A smiling man in a navy sweater sits at a light wooden counter looking down at an open silver Surface laptop with the Microsoft logo on its lid; a tan mug and a pastry on a plate sit beside it, and wooden shelves with plants are out of focus behind him.
Photo: Microsoft · A smiling man in a navy sweater sits at a light wooden counter looking down at an open silver Surface laptop with the Microsoft logo on its lid; a tan mug and a pastry on a plate sit beside it, and wooden shelves with plants are out of focus behind him.

Microsoft released Windows 11, version 26H2, on September 29, and on a PC that is up to date it is barely a download. Microsoft's announcement, by John Cable, its vice president for Windows servicing and delivery, says eligible PCs on versions 25H2 and 24H2 get "a small enablement package" and "a single restart." What the new number buys is time: Microsoft's schedule ends updates for the Home and Pro editions of 24H2 on October 13. If you keep Windows 11 on a Mac, check which version it is.

The update is a 174KB switch

Microsoft's support note for KB5121794 says versions 24H2, 25H2 and 26H2 share "an identical set of system files," that the new features arrive dormant in the monthly updates, and that the package is a "master switch" that turns them on. According to this Windows Latest article, the switch is 174KB and 26H2 "comes with NOTHING new for consumers." Among its features, Microsoft's what's-new page lists a taskbar that can sit at the bottom, top, left or right, which our September 9 Dark Side item reported was not in that month's patch.

Microsoft's release information page listed 26H2 on October 3 as build 26300.9550, with updates for Home and Pro until October 10, 2028, and gives October 13, 2026 as the end of updates for 24H2 Home and Pro. Microsoft's known-issues page says the rollout is phased, and on October 2 it added a confirmed bug: applications that need AC-3 audio decoding may close unexpectedly after the September 22 update, on 24H2 and 25H2 as well as 26H2.

A Mac's Windows is on the same clock

Microsoft's support page for Macs with M1, M2 and M3 chips names Parallels Desktop as an authorized way to run the Arm versions of Windows 11 Pro and Enterprise in a virtual machine, and the Parallels Desktop 27 guide says those are the editions it installs on Apple silicon. Microsoft's table sets its dates by version and edition, so by our reading a Pro virtual machine still on 24H2 reaches the end of its updates on October 13. Settings > System > About shows the version, and Windows Update offers 26H2 once the rollout reaches you.

In our October 9, 1997 item on MacWinNuke, a reader reported that "service pack 3 for NT does not fix the problem," a bug that let anyone crash a Windows 3.1, 95 or NT machine by its IP address, and that the Mac OS was not affected. Twenty-nine years later, by our count, the yearly Windows update is a 174KB switch that changes a version number, and we think it is the most honest feature update Microsoft has shipped.

Sources

  1. Windows Blogs, “How to get the Windows 11 2026 Update | Windows Experience Blog” accessed Oct 3, 2026The September 29, 2026 announcement of Windows 11, version 26H2, by John Cable, Vice President, Product Management, Windows Servicing and Delivery; eligible devices on versions 25H2 and 24H2 get "a small enablement package" with "a single restart"; an eligible device sees the option to download and install version 26H2 in Windows Update; installing version 26H2 resets the support lifecycle; the header photograph; accessed October 3, 2026.
  2. Microsoft Support, “KB5121794: Feature update to Windows 11, version 26H2 by using an enablement package” accessed Oct 3, 2026Versions 24H2, 25H2 and 26H2 share a common core operating system with "an identical set of system files"; the new features are included in the monthly quality updates in a dormant state; the enablement package is a "master switch" that activates them; accessed October 3, 2026.
  3. Windows Latest, “Windows 11 26H2 is now rolling to everyone, how to get it right now, and is it even worth installing?” accessed Oct 3, 2026Mayank Parmar's September 29, 2026 report: the update is 174KB on a PC with the recent monthly cumulative updates; "Windows 11 26H2 comes with NOTHING new for consumers"; the enablement package changes the OS version and build number; Settings > System > About shows the installed version; accessed October 3, 2026.
  4. Microsoft, “What's new in Windows 11, version 26H2 for IT pros” accessed Oct 3, 2026Version 26H2 activates and consolidates features delivered through monthly updates; among them, users can position the taskbar at the bottom, top, left or right side of the screen; accessed October 3, 2026.
  5. Microsoft, “Windows 11 - release information” accessed Oct 3, 2026As read on October 3, 2026: version 26H2 available 2026-09-29, latest build 26300.9550, end of updates for Home and Pro 2028-10-10; version 24H2 end of updates for Home and Pro 2026-10-13; the table sets its dates by version and edition.
  6. Microsoft, “Windows 11, version 26H2 known issues and notifications” accessed Oct 3, 2026The rollout is phased; the known issue opened and confirmed on October 2, 2026: after the updates released September 22, 2026 (KB5124010) and later, some applications that require AC-3 audio decoding might close unexpectedly, affecting versions 26H2, 25H2 and 24H2; accessed October 3, 2026.
  7. Microsoft Support, “Options for using Windows 11 with Mac computers with Apple M1, M2, and M3 chips” accessed Oct 3, 2026Parallels Desktop named as an authorized solution for running Arm versions of Windows 11 Pro and Windows 11 Enterprise in a virtual environment on Apple M1, M2 and M3 computers; accessed October 3, 2026.
  8. Parallels, “What Versions of Windows You Can Install | User's Guide | Parallels Documentation” accessed Oct 3, 2026Parallels Desktop for Mac 27 supports installing the Windows 11 Pro and Enterprise editions designed for Arm processors, on Macs with Apple silicon; accessed October 3, 2026.

Then and now

All pairings

In 1997 a reader warned that Service Pack 3 for NT did not fix a bug that crashed Windows from afar; in 2026 the yearly Windows 11 update is a 174KB switch that resets the support clock.

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