Windows 11 26H2: Release Date, Download (ISO or the 174 KB Switch), What's New, Known Issues, Install Errors and How to Go Back (Updated October 24, 2026)

Windows 11 26H2, the Windows 11 2026 Update, has been out since September 29, 2026, and as of October 21 it is offered to every eligible PC on 24H2 or 25H2. Check for it in Settings, Windows Update, select Download & install under "Windows 11, version 26H2 is available," and restart once. Here is the part that surprises people: on a PC that is already up to date, that "upgrade" is a download of roughly 174 KB. Everything in 26H2 was already installed by the September and October monthly updates; the package is a switch that turns the new version on and moves your end-of-updates date to October 10, 2028. The full ISO exists too, for clean installs and for PCs on 23H2 or Windows 10. This page covers both routes, what is actually new, the five known issues, the errors that stop the install, and how to go back.

Last checked: October 24, 2026. This is a living page: the dates table, the known-issues list and the build numbers are rechecked after every Patch Tuesday, and each change is logged at the bottom.

Jake runs a phone repair shop, and this week a regular brought in a laptop with a question rather than a cracked screen: a box in Settings kept offering "Windows 11, version 26H2," and she wanted to know whether it was one of those updates that changes everything. Jake called his friend Ethan, a developer who looks after the shop's PCs. Ethan asked her to press the button while they watched. The download took a few seconds, the restart took about a minute, and the laptop came back looking exactly the same. "That's it?" Jake asked. "That's it," Ethan said. "The new version was already on the laptop. She just turned it on." This page is what Ethan explained over the counter, written down so you can follow it on your own PC. If you're not sure which version you have now, our guide to finding your build number shows it with winver in ten seconds.

Is Windows 11 26H2 out? Release date, build numbers and who gets it

Yes. Windows 11, version 26H2 reached general availability on September 29, 2026. The first build to carry the new version number was 26300.9457; the September 22 preview update KB5124010 took it to 26300.9550, and the October 13 security update KB5127648 took it to 26300.9711, which is the current build as of this page's last check. The rollout started as a controlled feature rollout, where PCs with a known compatibility problem are held back, and on October 21 the release health page for 26H2 marked it as fully available for every eligible PC running 24H2 or 25H2. In plain terms: if you're on 24H2 or 25H2 and you press Check for updates today, you should see it.

Two rows in that table decide what you should do next. If you're on 24H2 Home or Pro, you received your last security update on October 13, 2026; moving to 25H2 or 26H2 is how you keep getting them, and 26H2 is the one Windows Update offers. If you're on 25H2, there's no rush: you're protected until October 12, 2027, and 26H2 is a free option you can take when it suits you. The odd one out is 26H1. It shipped in February 2026 only on new Arm PCs built around chips like the Snapdragon X2, it uses a different Windows core (build 28000), and it is not offered to existing PCs. Going the other way is also closed: a 26H1 PC cannot take 26H2, and gets its own monthly updates instead, such as KB5127646 in October.

Jake: "So her laptop was on 24H2 and quietly ran out of updates two weeks ago?"

Ethan: "Right. Nothing broke on the day, which is why nobody notices. The box in Settings was the fix, sitting there waiting to be pressed."

What Windows 11 26H2 actually is: a 174 KB switch, not a new Windows

Windows 11 24H2, 25H2 and 26H2 share one set of core system files. Microsoft calls this a shared servicing branch, and it changes what a "version upgrade" means. All through 2026, the monthly updates for 24H2 and 25H2 have been carrying the 26H2 code inside them, switched off. The feature update to 26H2 is an enablement package, KB5121794, a small .msu that flips those features on, changes the version string to 26H2, and resets your support lifecycle. The x64 and Arm64 packages are listed at about 174 KB each. Compare that with the 5 GB cumulative update that KB5127648 shows in the Update Catalog, and you see why the restart feels like a normal Patch Tuesday rather than the hour-long in-place upgrades of the Windows 10 years.

This explains three things people find odd. First, the prerequisite: KB5121794 needs the September 22, 2026 preview update KB5124010, or any later cumulative update, already installed, because that is where the dormant 26H2 code lives. Second, the install date: Settings, System, About still shows the date Windows was originally installed, because nothing was reinstalled; a full ISO upgrade changes that date, the switch does not. Third, the missing features: some 26H2 features arrive through a controlled feature rollout and switch on over weeks, so two PCs on the same build can look different. More on that in the what's new section.

Use the table below to tell the two routes apart before you pick one.

Jake: "So when people say 26H2 is 'light' and 'fast,' they mean the install, not Windows?"

Ethan: "Mostly, yes. The code was already running on their PC last month. Some people do measure less memory used at boot after the switch, but that comes from features being turned on and off, not from a new Windows."

How to get Windows 11 26H2 through Windows Update (and what "not showing" means)

Follow these steps on a PC running 24H2 or 25H2. Plug in a laptop first; the restart is short, but a dead battery halfway through a feature update is the one way to make a simple thing complicated.

1. Press Windows + I to open Settings, then select Windows Update in the left column.
2. Select Check for updates. Let any pending cumulative update install first and restart if asked; KB5124010 or later must be on the PC before the 26H2 package will appear.
3. Look for the box titled "Windows 11, version 26H2 is available" near the top of the page. Select Download & install.
4. The download finishes in seconds. Select Restart now, or leave it for the next restart; the switch happens during that one restart.
5. After sign-in, press Windows + R, type winver, press Enter. You should see Version 26H2 (OS Build 26300.9711).

26H2 not showing in Windows Update? Work through this list

Since October 21 the rollout is at full availability, so a PC that still isn't offered 26H2 has a reason you can usually find.

1. Turn on the early toggle. On the Windows Update page, switch on Get the latest updates as soon as they're available, then check again. This is the setting that puts a PC at the front of the rollout queue.
2. Install the prerequisite. Open Update history. If KB5124010 (build .9550) or KB5127648 (build .9711) isn't listed, the PC hasn't got the code the switch turns on. Install the pending cumulative update, restart, check again.
3. Check your current version. winver showing 23H2 (build 22631) or Windows 10 (build 19045) means the enablement package doesn't apply; use the ISO or Installation Assistant route in the next section. Build 28000 means 26H1, which can't take 26H2 at all.
4. Look for a safeguard hold. If a driver or app on your PC has a known conflict, Windows Update shows a note under the update that the upgrade is on its way but held for your device. The hold lifts when the fix ships; forcing past it with an ISO is how people meet the problem the hold was protecting them from.
5. Check who manages the PC. A work or school PC under Intune, Autopatch or WSUS gets 26H2 when the administrator releases it. The Windows Update page says "Some settings are managed by your organization" when that's the case.
6. Free up space and retry. The switch itself is tiny, but the cumulative update it depends on isn't. Ten free gigabytes on C: is a comfortable floor.

Jake: "Her laptop showed it straight away. My own desktop at the shop doesn't. Same Windows."

Ethan: "Open Update history on the desktop. I'd bet it's still waiting to install the October update; the 26H2 box only appears after that one is in."

Windows 11 26H2 download: ISO, Installation Assistant, Media Creation Tool, and the free part

Everything on this list is free from Microsoft; "Windows 11 26H2 free download" sites that ask for a payment, an account or a "downloader" app are selling you something you already own. The official page is microsoft.com/software-download/windows11, and as of October 24 its heading reads "Windows 11 2026 Update l Version 26H2," so anything you fetch from it today is 26H2. Pick the route that matches what you're doing:

Getting the ISO and checking it

On the download page, scroll to Download Windows 11 Disk Image (ISO) for x64 devices, select the multi-edition ISO, confirm, choose your language, confirm again, then select the 64-bit download button. The link it generates is valid for 24 hours. The same page has a Verify your download section with a SHA256 value per language; check yours in PowerShell before you build media:

Get-FileHash "$env:USERPROFILE\Downloads\Win11_26H2_English_x64.iso" -Algorithm SHA256

If the hash differs from the page, the download is damaged or tampered with; delete it and fetch it again. Our ISO download guide walks through the page with screenshots, including the trick for getting the ISO link from a phone or a Linux PC when the page insists on offering the Media Creation Tool.

Does the ISO install 26H2 or 25H2?

Today's ISO installs 26H2 directly at build 26300.9457, and the first Windows Update run takes it to 26300.9711. Media you downloaded before September 29 installs 25H2 or 24H2 and then offers the 26H2 switch after the first round of updates, so there's no need to throw away an older USB stick; it just means two restarts instead of one.

What's new in Windows 11 26H2 (and why much of it was already on your PC)

If you expect a new look, you'll be disappointed, and that's by design: 26H2 consolidates a year of features that monthly updates already delivered, and turns on a few that were held behind temporary commercial controls. Here is what's in it, grouped by who notices.

Things you can see

• Taskbar anywhere. Position it at the bottom, top, left or right, and choose a smaller taskbar that shrinks icons and height. A taskbar panel can also monitor supported AI agents and tell you when a long task finishes; Researcher in Microsoft Copilot is the first.
• Redesigned Start menu. A scrollable All section, category and grid views, a choice of menu size, and separate switches to show or hide Pinned, Recent and All.
• File Explorer. AI actions on supported images and documents (the Summarize action needs a Microsoft 365 subscription with a Copilot license), hover actions such as Open file location for work and school accounts, new archive formats (uu, cpio, xar, nupkg), View and Sort settings that stick in Downloads and Documents, voice typing while renaming, and a faster Home view.
• Windows Search. Previews without opening, app search that forgives typos and partial names, clearer labels for app, setting, file, web and Store results, and automatic indexing of folders you use often (Settings, Privacy & security, Search).
• Windows Update behavior. Eligible updates install together with the monthly security update to cut restarts, and a PC you put to sleep manually goes back to sleep after updating even when sleep is set to Never.
• Camera, Bluetooth and USB. Multi-App Camera lets two apps use the webcam at once; Basic Camera mode is a plain fallback for troubleshooting; Bluetooth LE Audio, call quality, mute sync and reconnection after hibernation improve; displays behind USB4 docks wake up more reliably.
• Accessibility. Magnifier accepts an exact zoom percentage and a full-screen color tint; Narrator gains a Braille Viewer and better Word navigation; Voice access adds French, German, Spanish and Korean, with natural-language commands on Copilot+ PCs.

Things that protect you without a setting

• Administrator protection gives administrators just-in-time elevation with a separate profile instead of standing admin rights. It's off by default on home PCs; it is on by default in Microsoft's security baselines for 24H2, 25H2 and 26H2, which matters in the known issues section.
• Sysmon built in, off by default, for anyone who wants detailed event logging without downloading it.
• Smart App Control can be turned on or off without a clean install.
• Passkeys can live in a third-party credential manager, and Windows Hello Enhanced Sign-in Security now works with external fingerprint readers.
• Driver trust changes: cross-signed drivers lose default trust in favor of WHCP-signed drivers plus an allow list, after an audit of at least 100 hours and three restarts on each PC.
• Post-quantum cryptography APIs (ML-KEM and ML-DSA) for developers.
• Point-in-time restore rolls a PC, including apps, settings and files, back to a recent automatic restore point; quick machine recovery can run a one-time remediation scan when Windows won't start.

Something that's gone: WMIC

The WMIC command-line tool is removed in 26H2 and is no longer offered as a Feature on Demand on 24H2 and above. Scripts and support articles that start with wmic bios get serialnumber fail with "'wmic' is not recognized." Our WMIC replacement guide has the PowerShell equivalent for every common WMIC command.

Why your PC may not show all of this yet

A user who installed 26H2 on launch day got the movable taskbar at once but no Start menu options, and asked whether the update had only half installed. It hadn't. Several 26H2 features ship through a controlled feature rollout, where Microsoft turns them on for a growing share of PCs over weeks and watches for problems; two PCs on build 26300.9711 can differ for a while. If a feature matters to you, the early-updates toggle on the Windows Update page also opts you into these rollouts sooner. Features that appeared in Insider previews but never reached the shipping 26H2 feature list, such as the context menu "Customize" option, aren't part of 26H2 yet, and no date has been given.

Jake: "So the customer who asks why her neighbor's Start menu looks different is going to get 'wait a few weeks' from me?"

Ethan: "Yes, and it's the honest answer. The switch is the same on both PCs; the features behind it light up on Microsoft's schedule."

Windows 11 26H2 vs 25H2 vs 24H2 vs 26H1: the differences that matter

The practical reading: 26H2 and 25H2 are the same Windows with different switches set and different end dates. Choosing between them is choosing between October 2027 and October 2028, plus the handful of features above. 24H2 is where you shouldn't stay on a Home or Pro PC. 26H1 isn't a choice at all; it came with the PC or it didn't.

Do the system requirements change in 26H2?

No. The published minimums are the ones from 24H2: a 1 GHz, 2-core, 64-bit CPU from the supported lists (8th-generation Intel Core, Ryzen 2000 and newer, selected Snapdragon chips), 4 GB of memory, 64 GB of storage, UEFI with Secure Boot capability, TPM 2.0, DirectX 12 graphics with a WDDM 2.0 driver, and a 720p display larger than 9 inches. The CPU also has to support the POPCNT instruction and SSE4.2, a check that arrived with 24H2 and stops Windows booting on processors made before about 2007. If Setup says your PC doesn't meet the requirements, our requirements guide covers the TPM and Secure Boot settings that fix most of those messages without new hardware. Copilot+ features, such as natural-language Voice access, still need a Copilot+ PC: a 40+ TOPS NPU, 16 GB of memory and a 256 GB SSD.

Windows 11 26H2 known issues (the October 21, 2026 list) and what to do about each

The release health page for 26H2 lists five issues. Three are resolved by updates you likely already have; two are open. Check whether any applies to you before you press the button, and after you've pressed it, use this list to match a symptom to a fix.

USB audio: "This device cannot start (Code 10)"

After the September updates, and so after 26H2, some USB Audio Class 1.0 devices fail to start, play nothing, keep the volume at zero or make the Sound settings page unresponsive. The problem is limited to Class 1.0 devices, which covers many older interfaces and a good number of budget DACs and headsets. An out-of-band update covered part of it; the rest is still open, and the only official route for the remaining cases on a managed PC is Microsoft Support for Business. For a home PC, the practical fixes are in our USB audio Code 10 guide: the generic driver swap, the hub change and, as a last resort, pausing updates until the fix lands. This issue is the one real reason for a home user to wait.

Remote Desktop: error 0xC000000D, "The token that was passed to the function is invalid"

Since KB5124010, a standard (non-admin) user who connects by Remote Desktop to a PC where Administrator protection is enabled can be refused with this error. Home PCs have the feature off, so this is mostly a work problem, but it bites hard there because Microsoft's security baselines for 24H2, 25H2 and 26H2 turn Administrator protection on by default. The workaround is to turn the feature off on the host through Intune or Group Policy (the policy is "User Account Control: Type of Admin Approval Mode") until the fix arrives in a later update. Scripts circulating online that change registry values under the hood do the same thing with less control; use the policy.

AC-3 audio: games and players that crash

Between September 22 and October 13, applications that rely on the Windows built-in AC-3 (Dolby Digital) decoder could fail to open or close without warning, sometimes only when music started. Older games and media players were the typical victims; modern apps bring their own decoders and were unaffected. KB5127648 resolved it. If a game started crashing after 26H2 and you're on build 26300.9550, the October update is the fix, not a rollback.

Jake: "Two open issues, both about work PCs or old audio gear. For her laptop, that's nothing?"

Ethan: "For her laptop, nothing. For the shop's recording interface, I'd check the box before switching the studio PC."

Windows 11 26H2 not installing: errors 0x80246017, 0x80246019, "Undoing changes" and stuck downloads

Because the 26H2 switch rides on the cumulative update underneath it, most "26H2 won't install" cases are really "the monthly update won't install." Match your symptom first.

Download errors 0x80246017 and 0x80246019

Both codes belong to the download manager stage, before anything is installed: Windows Update could not fetch or verify the files. They show up with feature updates more than monthly ones because the files are larger and come from more places. Work through this list, checking after each step:

1. Run the built-in fixer: Settings, System, Troubleshoot, Other troubleshooters, Windows Update, Run.
2. Free up space on C: until you have at least 10 GB, then restart.
3. Pause any third-party antivirus or VPN for the duration of the download; both can block or rewrite the download stream.
4. Reset the update components from an elevated Command Prompt:

   net stop wuauserv
   net stop bits
   net stop cryptsvc
   ren %systemroot%\SoftwareDistribution SoftwareDistribution.old
   ren %systemroot%\System32\catroot2 catroot2.old
   net start cryptsvc
   net start bits
   net start wuauserv

   Then check for updates again.
5. If it still fails, skip Windows Update: download the ISO, mount it, run setup.exe and choose to keep files and apps. This in-place upgrade uses its own download and is the route that works when the update service won't.

"Undoing changes made to your computer"

This message means the install reached the restart stage and rolled back. Windows keeps the reason in C:\$WINDOWS.~BT\Sources\Panther\setuperr.log for full upgrades, and in Update history as a failed entry with an error code for the enablement package. The usual causes, in order: a driver that blocks the upgrade (update it from the maker's site, or uninstall it for the duration), a disk with corrupted system files, and third-party encryption or disk tools. Run these two repairs from an elevated Command Prompt, restart, and retry:

DISM /Online /Cleanup-Image /RestoreHealth
sfc /scannow

If the cumulative update that 26H2 needs is the one failing, our guides for 0x800f0922 and 0x80073712 cover the two most common codes, and the stuck at 100% guide covers the restart loop.

Stuck at "Pending install" or 0% for hours

Leave it for an hour first; the cumulative update underneath can sit at a low percentage while it stages files. After that, restart the PC once and check for updates again, then run the component reset above. A PC that sits at 0% for days usually has a stopped or disabled Windows Update service or a metered connection; check Settings, Network & internet, your connection's properties, for the Metered connection switch, because Windows won't fetch feature updates over a metered link unless you allow it.

How to check whether you're on 26H2: winver, Settings, PowerShell and DISM

Pick whichever is handy; they all read the same values.

• winver: Windows + R, winver, Enter. Look for "Version 26H2 (OS Build 26300.9711)." A build starting 26200 is 25H2, 26100 is 24H2, 28000 is 26H1.
• Settings: System, About, under Windows specifications. The Installed on date stays at the original install date after the enablement package; that's expected.
• PowerShell:

  Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows NT\CurrentVersion" | Select-Object DisplayVersion, CurrentBuild, UBR

  DisplayVersion 26H2, CurrentBuild 26300, UBR 9711 is today's fully updated state.
• Was the switch installed? In Settings, Windows Update, Update history, the package appears under Feature updates as "Windows 11, version 26H2." From an elevated prompt, DISM /Online /Get-Packages | findstr 5121794 lists the package if it's present.

For a room full of PCs, systeminfo | findstr /B /C:"OS Version" over a remote session, or the Intune device report, gets you the same answer without touching each screen.

How to uninstall Windows 11 26H2 or go back to 25H2

How you went up decides how you come down, and the two routes have different clocks.

You installed it from Windows Update (the enablement package)

1. Open Settings, Windows Update, Update history.
2. Under Related settings, select Uninstall updates.
3. Find the entry for the 26H2 feature enablement package, KB5121794 (it was listed as "Feature Enablement for Windows (Ge)" when this was last checked; the label can change), select Uninstall, confirm, and restart.

The PC returns to 25H2 or 24H2 at the same build revision, with files, apps and settings intact, because nothing but the switch is removed. The monthly updates stay installed. You can take the switch again later from the Windows Update page.

You installed it from an ISO, the Installation Assistant or from Windows 10

1. Open Settings, System, Recovery.
2. Under Recovery options, select Go back, pick a reason, select Next, then Go back to earlier build.

This option exists for 10 days after the upgrade, while the previous Windows is kept in Windows.old; after that, or if you've run Disk Cleanup on system files, reset the PC or added a user account, the button is gone and the only way back is a clean install of the older version plus your backup. Personal files survive the go-back; apps, drivers and settings changed after the upgrade are removed. A clean install of 26H2 has nothing to go back to. Our uninstall-an-update guide covers the recovery-environment route for a PC that won't start at all.

Jake: "Ten days is tight if someone only notices a problem when they do their month-end invoices."

Ethan: "Which is why, for the switch route, the clock doesn't matter: the uninstall button stays. It's only the full upgrades that have the 10-day limit."

Should you install Windows 11 26H2 now, or stay on 25H2?

Decide from your version and your gear, not from headlines.

One more thing worth saying plainly, because a reader asked it: if you can't or won't install 26H2 on a 25H2 laptop that only browses the web, you are not at risk for another year. The risk is staying on a version after its end date, and 25H2's is October 12, 2027. Put a reminder in your calendar for September 2027 and carry on.

For IT admins: deploying Windows 11 26H2 with WSUS, Intune, Autopatch, and the traps in the baseline

Treat 26H2 as a servicing event, not an OS migration, and your validation shrinks to the features it switches on. The points that cost people time in October:

• Channels. The enablement package is in Windows Update, Windows Update for Business, Windows Autopatch and WSUS (Product: Windows 11; Classification: Upgrades; title "Windows 11, version 26H2"). It is not in the Microsoft Update Catalog, so there's no .msu to import into Configuration Manager by hand; sync the Upgrades classification instead. In Intune, use a feature updates policy targeting "Windows 11, version 26H2," which also gives you per-group timing and the deployment report.
• Prerequisite. Devices must have KB5124010 or a later cumulative update. A ring that's a month behind sees nothing until the October update is in.
• Baseline trap. The Windows 11 26H2 security baseline enables Administrator protection by default. Applied to Remote Desktop hosts, it triggers the open 0xC000000D issue for standard users. Scope it, or set "User Account Control: Type of Admin Approval Mode" back to legacy on hosts until the fix ships.
• Profile separation. With Administrator protection on, elevation runs under a separate, system-managed admin profile; users notice a new C:\Users\ADMIN_username folder and ask why. That's the feature working, and the folder name follows the account name rather than any custom profile folder name you set.
• Known Issue Rollbacks. Two KIR policies are published for 26H2: "KB5124008 260915_17123 Known Issue Rollback" for the domain trust issue (superseded by KB5124010) and "KB5124010 260924_20021 Known Issue Rollback" for the AVD black-screen issue (superseded by KB5127648). If your fleet is on the October update you don't need either; if you deployed them, plan to remove them.
• Driver trust change. Cross-signed drivers lose default trust after a 100-hour, three-restart audit per device. Check your LOB hardware drivers for WHCP signatures now, before the audits end.
• WMIC removal. Inventory scripts, login scripts and old RMM checks that call wmic break. The replacement table maps each call to Get-CimInstance.
• Sysmon and the batch-file hardening. Both are off by default and both are worth a pilot: built-in Sysmon removes a deployment step, and the secure processing mode for .bat and .cmd files stops a script being modified while it runs.
• 26H1 devices. Snapdragon X2 class hardware stays on 26H1 (build 28000) with its own updates and its own March 2028 end date. Build your reports with two version columns, or they'll look like failures.
• Hotpatch. 26H2 has a hotpatch calendar: a baseline cumulative update with a restart in the first month of each quarter, restart-free security hotpatches in the other two months, for Enterprise devices enrolled through Autopatch.

Pilot on a ring that includes one Remote Desktop host, one PC with a USB audio device, and one domain-joined PC with Credential Guard, and the three issues that have bitten other fleets show up in your pilot rather than your help desk.

Every Windows 11 date that matters after 26H2

Still on Windows 10? The Windows 10 ESU dates page explains the one-year extension to October 12, 2027 and what it costs, which is the deadline that should drive your 26H2 plan.

Windows 11 26H2: frequently asked questions

The customer's laptop went home on 26H2 with an end-of-updates date two years out, and she still hasn't noticed a difference, which is the point. Jake moved his own shop desktop the next morning once the October update had finished, checked the recording interface against the known-issues list first, and found it was Class 2.0, so it went too. Ethan wrote the line below on the whiteboard behind the counter, where customers can read it while they wait.

Changes to this page

• October 24, 2026: first version. Builds as of KB5127648 (26300.9711); known-issues list as of October 21, 2026; download page heading "Windows 11 2026 Update l Version 26H2."

Revision note. Written October 24, 2026, for everyone who stared at the "Windows 11, version 26H2 is available" box and wondered what would change. "Still waters run deep," says the old proverb; the quietest update of the year carries two more years of protection.