Windows 11 26H2: what is new, how to install the 2026 Update and what to do when it does not show up

What is Windows 11 26H2 and why is the update so small?

Windows 11 26H2 is the annual feature update for 2026, which Microsoft also calls the Windows 11 2026 Update. Microsoft made it generally available on 29 September 2026 for PCs running Windows 11 version 24H2 and 25H2 (Windows Experience Blog). The name follows the usual logic: 26 is the year, H2 the second half.

Unlike the big upgrades of the past, 26H2 is not a new version of Windows that rebuilds your PC. Versions 24H2, 25H2 and 26H2 share the same code. New features have been delivered to your PC through the monthly updates over the past year, some visible, some dormant. The 26H2 update is an enablement package, which Microsoft describes as a small, quick-to-install master switch that turns the dormant features on (Microsoft Support, KB5121794). That is why the download is small, the installation feels like a regular monthly update and a single restart is enough.

The build number makes the difference visible: 24H2 is build 26100, 25H2 build 26200 and 26H2 build 26300. The number after the dot is the monthly update and moves in step for all three. That tells you at a glance whether the update worked.

Do you see version 26H1 on a new laptop? That is a separate release for devices that came to market in early 2026. Microsoft does not offer 26H1 as an update for existing PCs, and you do not need to do anything with it (Microsoft Learn).

Why you should update now: 24H2 ends on 13 October 2026

Every Windows 11 version has a fixed support period: 24 months for Home and Pro, 36 months for Enterprise and Education. After that, security updates stop. For Windows 11 24H2 Home and Pro that date is 13 October 2026, two weeks after 26H2 appeared. From that day on, anyone still on 24H2 is running a system whose new vulnerabilities go unpatched.

Unlike Windows 10, there is no paid or free extension for an old Windows 11 version. Nor is one needed: updating to 25H2 or 26H2 is free and takes a few minutes. Microsoft releases the new version every autumn, shortly before the version from two years earlier leaves support. This year the gap is exactly two weeks.

Still on 23H2 or on Windows 10? Then the story is different: your PC does not get a small enablement package but a full upgrade. More on that below under the update does not appear.

What is new in 26H2?

Let's be honest: after the update your desktop looks the same. Microsoft itself calls 26H2 a "predictable, low-disruption update" that bundles the features which trickled into 24H2 and 25H2 over the past year (Windows IT Pro Blog). What does change the moment you install 26H2 is that a number of features that were still off in 25H2 are now on by default. These are the changes a home user or business owner will run into first.

For businesses the real gain lies in security and management: Administrator protection (admin rights only at the moment you need them), Smart App Control that you can now switch on and off without reinstalling, first support for post-quantum cryptography and stricter rules for drivers. More on that in the section for business owners.

Before you start: four things to check

• Back up your files

  The chance of trouble with an enablement package is small, but not zero. Copy your documents and photos to an external drive, or check that OneDrive has synced everything. A backup that turns out to be unnecessary is never wasted time.

• Make sure you have power and a good connection

  Plug a laptop into its charger and use a wired connection or solid Wi-Fi where possible. A PC that loses power halfway through an update is a common cause of Windows no longer booting.

• Check the free space

  The 26H2 update itself is small, but Windows needs room to unpack the installation and keep a way to roll back. Keep at least 10 GB free on the C: drive. Error code 0x80070070 during an update means: disk full.

• On a work PC, talk to your administrator first

  If your PC is managed through Intune or a domain, the IT administrator decides when 26H2 is rolled out. The toggle from step 3 is often greyed out. Ask them rather than reaching for installation media yourself.

Step 1: check which version of Windows 11 you have

After this step you know whether your PC gets the small 26H2 update or needs a full upgrade. Open Settings → System → About and look under Windows specifications for the Version line. Faster: press Windows + R, type winver and press Enter.

Step 2: install every pending update first

After this step the update of 22 September 2026 (KB5124010) or a newer monthly update is on your PC, and that is a hard requirement: the enablement package only installs on a PC with that update or later (Microsoft Support, KB5121794). Go to Settings → Windows Update, click Check for updates, install everything that is waiting and restart. If something new is offered afterwards, repeat until the message "You're up to date" appears.

Note: KB5124010 is the optional update of 22 September. Windows does not install it by itself; it sits under Windows Update → Advanced options → Optional updates. If it is listed there, install it as well. From the regular monthly update of 13 October 2026 onwards the same content is part of the mandatory update and this extra step is no longer needed.

Step 3: turn on the toggle for the latest updates

After this step your PC is at the front of the queue. Microsoft rolls 26H2 out in phases over several months and starts with PCs where the toggle Get the latest updates as soon as they're available is on (Microsoft, release health 26H2). You find that toggle at the top of Settings → Windows Update. Set it to On.

Good to know: with this toggle on, your PC also receives other non-security updates earlier, and Microsoft warns that this can mean more restarts per month (Microsoft Support). Security updates always arrive, whether the toggle is on or off. After the 26H2 installation you can safely switch it off again.

Step 4: download and install Windows 11, version 26H2

After this step 26H2 is on your PC and Windows is only waiting for a restart. In Windows Update, click Check for updates. If the update is ready for your PC, a panel appears with the text Windows 11, version 26H2 is available and the button Download & install. Click it. On PCs with the toggle from step 3 on, Microsoft says Windows may also download and install the update by itself.

The download is small and the installation takes a few minutes. No panel? That is normal in the first weeks. Read the update does not appear before trying anything else.

Step 5: restart once and verify the version

After this step your PC runs 26H2. Click Restart now as soon as Windows offers it. The restart takes a little longer than usual, but you will not sit through minutes of percentage counters as you would with a full upgrade. Then open Settings → System → About: the Version line reads 26H2 and the build number starts with 26300. Finally, walk through Settings → Accounts → Windows Backup and System → Recovery to see whether the new defaults suit you.

The update does not appear: the likely causes

Not seeing 26H2 in Windows Update is the rule rather than the exception in the first weeks. Work through these causes from top to bottom.

• It is simply not your PC's turn yet

  Microsoft rolls 26H2 out in phases and widens the group over the coming months. With the toggle from step 3 on you are at the front, but not everyone gets it on day one. Check every few days; forcing it with installation media is neither necessary nor wise.

• There is a safeguard hold (a block by Microsoft) on your PC

  If Microsoft sees a known compatibility problem with a driver or app on your type of PC, the update is deliberately held back until it is solved. Windows Update sometimes says the update is not yet ready for your device. Bypassing that with an ISO pulls in exactly the problem the hold is meant to prevent.

• Your PC runs 23H2 or older

  The enablement package only works on 24H2 and 25H2. A PC on 23H2 receives a full upgrade to a newer version through Windows Update, which takes more time and space. If it is not offered, use Microsoft's Installation Assistant.

• Your PC runs Windows 10

  That is a full upgrade as well, and it requires TPM 2.0, Secure Boot and a supported processor. At the time of writing, Microsoft's download page still offered version 25H2; after that upgrade, 26H2 follows as a small enablement package.

• Your PC is managed by an IT partner

  On a PC with Intune, a domain or WSUS, the administrator controls the rollout. The toggle from step 3 is then greyed out or missing. Contact your IT partner.

Does Windows 11 reject your PC even though it is not old? Often it is just that TPM 2.0 and Secure Boot are switched off in the firmware; our guide to TPM 2.0 and Secure Boot (in Dutch) shows how to turn them on. That takes ten minutes.

Problems after the update and rolling back

Microsoft tracks the known issues for 26H2 on its release health page. On 29 September 2026 it listed three, all with the status "mitigated" and a permanent fix on the way (Microsoft Learn, Windows 11 26H2 known issues).

Rolling back 26H2

If the update really causes trouble on your PC, rolling back is straightforward. There are two routes, depending on how 26H2 arrived.

• 26H2 arrived as an enablement package (from 24H2 or 25H2)

  Go to Settings → Windows Update → Update history → Uninstall updates. Find the update with KB5121794 in its name, click Uninstall and restart. Your PC is back on the previous version, with all your files and apps.

• 26H2 arrived through a full upgrade (from 23H2 or Windows 10)

  Go to Settings → System → Recovery and choose Go back. In most cases this button works for ten days after the upgrade; after that Windows cleans up the old version. Your files stay, but apps and settings you changed after the upgrade are lost.

If the update itself hangs or ends in an error code, first use the built-in troubleshooter: Settings → System → Troubleshoot → Other troubleshooters → Windows Update. It resolves most stalls without you needing to understand what went wrong.

What 26H2 means for your business

For business owners, 26H2 is above all a planning moment. Windows 11 Pro gets the same 24 months of support as Home, so every workstation has to move up a version at least once every two years. The 24H2 end date of 13 October 2026 applies to Pro as well. Only Enterprise and Education get an extra year.

Microsoft advises businesses to test 26H2 on a few PCs with the programs you use every day before rolling it out widely (Windows IT Pro Blog). For an office with five to twenty workstations we translate that as: first the PC of the person who runs the accounting package, the till or the drawing software, a week later the rest.

Three things deserve your attention. First, Point-in-time restore is off by default on managed PCs; if you want that extra way back, your administrator has to switch it on deliberately. Second, Administrator protection is now available through Intune or Group Policy: staff then work without permanent admin rights, which sharply limits the damage of a wrong click. For businesses that fall under the Dutch Cyber Security Act (NIS2) (our explainer is in Dutch), this is a concrete measure to record in your compliance file. Third: if your network has its own domain with Windows Server, have the administrator read up on the known issue around Machine Identity Isolation before the rollout.

Frequently asked questions

Sources

All dates, build numbers and features in this article come from Microsoft's official documentation, retrieved on 29 September 2026. Microsoft adjusts the rollout and the list of known issues over time; the known-issues page is therefore the place to look if something behaves differently on your PC.

• Windows Experience Blog: How to get the Windows 11 2026 Update (29 September 2026)
• Microsoft Support: KB5121794, feature update to Windows 11, version 26H2 by using an enablement package
• Microsoft Learn: Windows 11 release information (versions, builds and end dates)
• Microsoft Learn: Windows 11, version 26H2 known issues and notifications
• Microsoft Support: Windows 11, version 26H2 update history
• Windows IT Pro Blog: An IT pro's guide to Windows 11, version 26H2 (29 September 2026)
• Windows Insider Blog: Releasing Windows 11, version 26H2 to the Release Preview Channel (27 August 2026)
• Microsoft Support: Get Windows updates as soon as they're available for your device
• Microsoft Support: Point-in-time restore for Windows
• Microsoft Support: Go back to the previous version of Windows
• Microsoft Support: Uninstall a Windows update
• Microsoft: Download Windows 11 (Installation Assistant, installation media and ISO)