Complete Windows 11 KB Update History: All Major Updates from 2021 to 2026 Explained
QUICK ANSWER Windows 11 has received hundreds of cumulative updates since its original release on 5 October 2021. Microsoft identifies most Windows updates w...
QUICK ANSWER
Windows 11 has received hundreds of cumulative updates since its original release on 5 October 2021.
Microsoft identifies most Windows updates with a KB (Knowledge Base) number, such as KB5006674, KB5028185, KB5044284, KB5066835, KB5101650, KB5121003, and KB5120998.
The most important point is that Windows 11 cumulative updates are cumulative. You normally do not need to install every historical KB one by one. Installing the latest applicable cumulative update normally includes fixes delivered by earlier cumulative updates.
As of 7 September 2026, the Windows 11 release families relevant to the complete update history are:
| Windows 11 version | Main OS build |
|---|---|
| 21H2 | 22000 |
| 22H2 | 22621 |
| 23H2 | 22631 |
| 24H2 | 26100 |
| 25H2 | 26200 |
| 26H1 | 28000 |
Windows 11 26H1 is a special newer release introduced in February 2026 and is not simply an ordinary in-place feature upgrade offered to existing 24H2/25H2 PCs. Microsoft currently lists 26H1, 25H2, 24H2 and supported editions of 23H2 in its servicing information.
This article provides a historical reference to the major Windows 11 operating-system cumulative KB releases and explains what each class of update primarily does.
COMPLETE ARTICLE
What Does KB Mean in Windows Update?
KB stands for Knowledge Base.
Microsoft assigns a Knowledge Base number to an update or support article, for example:
KB5120998
The KB number identifies the update package/documentation, while the OS Build tells you the resulting Windows build.
For example:
KB5120998 → Windows 11 24H2 build 26100.9278 / Windows 11 25H2 build 26200.9278
The same KB can therefore apply to more than one Windows 11 release.
Understanding B, D, Preview and OOB Updates
Microsoft's current servicing terminology makes the historical lists much easier to understand.
| Type | Meaning | Main purpose |
|---|---|---|
| B release | Second Tuesday monthly release | Security + quality fixes |
| D release | Later-month release, usually fourth week | Optional non-security improvements/preview |
| Preview | Optional preview cumulative update | Tests fixes/features planned for later rollout |
| OOB | Out-of-band | Urgent fix released outside normal schedule |
| Feature update | New Windows version | Moves Windows to a newer release |
| Enablement package | Small activation package | Enables features already staged in Windows |
| Hotpatch | Eligible enterprise servicing mechanism | Security servicing with fewer required restarts |
The monthly security update is normally the update ordinary users should prioritize.
Preview updates are generally optional unless you need a particular fix or want Microsoft’s newest non-security improvements before the following regular security update.
Windows 11 21H2 – Original Release
Windows 11 21H2 uses the 22000.x build family.
It was the original Windows 11 release.
2021 Windows 11 Updates
| Date | KB | Build | Primary purpose |
|---|---|---|---|
| 12 Oct 2021 | KB5006674 | 22000.258 | First regular Windows 11 cumulative security update |
| 21 Oct 2021 | KB5006746 | 22000.282 | Optional quality/compatibility fixes |
| 9 Nov 2021 | KB5007215 | 22000.318 | November security and reliability update |
| 22 Nov 2021 | KB5007262 | 22000.348 | Optional non-security fixes |
| 14 Dec 2021 | KB5008215 | 22000.376 | December security and quality update |
Microsoft records the original GA build as 22000.194; it did not have a normal cumulative-update KB in the release-history table.
Windows 11 Updates Released in 2022
Windows 11 21H2
| Period | KB | Build | Primary purpose |
|---|---|---|---|
| Jan B | KB5009566 | 22000.434 | Security cumulative update |
| Jan OOB | KB5010795 | 22000.438 | Emergency out-of-band corrections |
| Jan Preview | KB5008353 | 22000.469 | Optional quality fixes |
| Feb B | KB5010386 | 22000.493 | Security cumulative update |
| Feb Preview | KB5010414 | 22000.527 | Optional fixes/improvements |
| Mar B | KB5011493 | 22000.556 | Security update |
| Mar Preview | KB5011563 | 22000.593 | Non-security improvements |
| Apr B | KB5012592 | 22000.613 | Security update |
| Apr Preview | KB5012643 | 22000.652 | Optional fixes |
| May B | KB5013943 | 22000.675 | Security update |
| May Preview | KB5014019 | 22000.708 | Quality improvements |
| Jun B | KB5014697 | 22000.739 | Security update |
| Jun OOB | KB5016138 | 22000.740 | Emergency correction |
| Jun Preview | KB5014668 | 22000.778 | Optional fixes |
| Jul B | KB5015814 | 22000.795 | Security update |
| Jul Preview | KB5015882 | 22000.832 | Quality improvements |
| Aug B | KB5016629 | 22000.856 | Security update |
| Aug Preview | KB5016691 | 22000.918 | Optional fixes |
| Sep B | KB5017328 | 22000.978 | Security update |
| Sep Preview | KB5017383 | 22000.1042 | Optional quality update |
| Oct B | KB5018418 | 22000.1098 | Security update |
| Oct OOB | KB5020387 | 22000.1100 | Urgent correction |
| Oct Preview | KB5018483 | 22000.1165 | Optional fixes |
| Nov B | KB5019961 | 22000.1219 | Security update |
| Nov Preview | KB5019157 | 22000.1281 | Optional quality fixes |
| Dec B | KB5021234 | 22000.1335 | Security update |
These releases form the main 2022 servicing history for Windows 11 21H2.
Windows 11 22H2 Arrives
Windows 11 22H2 introduced the 22621.x build family.
Its first public build was 22621.521 in September 2022.
Important early updates included:
| Date/period | KB | Build | Purpose |
|---|---|---|---|
| 27 Sep 2022 | KB5019311 | 22621.525 | OOB servicing/update correction |
| 30 Sep 2022 | KB5017389 | 22621.608 | First major 22H2 preview servicing |
| Oct B | KB5018427 | 22621.674 | Security update |
| Oct OOB | KB5019509 | 22621.675 | Feature/experience enablement and fixes |
| Oct Preview | KB5018496 | 22621.755 | Optional improvements |
| Nov B | KB5019980 | 22621.819 | Security update |
| Nov Preview | KB5020044 | 22621.900 | Quality improvements |
| Dec B | KB5021255 | 22621.963 | Security update |
Windows 11 Updates Released in 2023
Two major Windows 11 servicing branches were active during 2023.
Windows 11 21H2 KB Updates in 2023
KB5022287, KB5019274, KB5022836, KB5022905, KB5023698, KB5023774, KB5025224, KB5025298, KB5026368, KB5026436, KB5027223, KB5027292, KB5028182, KB5028245, KB5029253, KB5029332, KB5030217, KB5030301, KB5031358, KB5032192 and KB5033369
These advanced the 22000 branch from build 22000.1455 in January to 22000.2652 in December.
The B releases primarily provided security fixes, while the C/D releases were mainly optional quality and reliability previews.
Windows 11 22H2 KB Updates in 2023
| Month | Security KB | Preview/optional KB |
|---|---|---|
| January | KB5022303 | KB5022360 |
| February | KB5022845 | KB5022913 |
| March | KB5023706 | KB5023778 |
| April | KB5025239 | KB5025305 |
| May | KB5026372 | KB5026446 |
| June | KB5027231 | KB5027303 |
| July | KB5028185 | KB5028254 |
| August | KB5029263 | KB5029351 |
| September | KB5030219 | KB5030310 |
| October | KB5031354 | KB5031455 |
| November | KB5032190 | KB5032288 |
| December | KB5033375 | — |
Important 2023 Change: Windows 11 23H2
Windows 11 23H2 uses build 22631.
Microsoft used enablement package KB5027397 to move eligible 22H2 installations to 23H2.
This is important because 22H2 and 23H2 shared much of the same underlying servicing platform, which is why many KB numbers applied to both versions.
Windows 11 Updates Released in 2024
Major 22H2/23H2 Cumulative KBs
| Month | Security update | Preview |
|---|---|---|
| Jan | KB5034123 | KB5034204 |
| Feb | KB5034765 | KB5034848 |
| Mar | KB5035853 | KB5035942 |
| Apr | KB5036893 | KB5036980 |
| May | KB5037771 | KB5037853 |
| Jun | KB5039212 | KB5039302 |
| Jul | KB5040442 | KB5040527 |
| Aug | KB5041585 | KB5041587 |
| Sep | KB5043076 | KB5043145 |
| Oct | KB5044285 | KB5044380 |
| Nov | KB5046633 | KB5046732 |
| Dec | KB5048685 | — |
These releases advanced the 22621/22631 servicing family and combined monthly security remediation with Windows reliability and feature improvements.
Windows 11 24H2 Begins
Windows 11 version 24H2 uses OS Build 26100 and became generally available in October 2024.
Important 24H2 releases in 2024 were:
| Date | KB | Build | Purpose |
|---|---|---|---|
| 8 Oct | KB5044284 | 26100.2033 | First major 24H2 security cumulative update |
| 24 Oct | KB5044384 | 26100.2161 | Optional quality improvements |
| 12 Nov | KB5046617 | 26100.2314 | Security update |
| 21 Nov | KB5046740 | 26100.2454 | Optional fixes |
| 10 Dec | KB5048667 | 26100.2605 | December security update |
24H2 itself introduced major platform improvements including Wi-Fi 7 support, Bluetooth LE Audio improvements, File Explorer changes, power-management improvements, Sudo for Windows and Remote Desktop improvements.
Windows 11 Updates Released in 2025
Windows 11 24H2 – Main 2025 KB History
| Period | KB | Build | Type / primary purpose |
|---|---|---|---|
| Jan B | KB5050009 | 26100.2894 | Security |
| Jan D | KB5050094 | 26100.3037 | Preview |
| Feb B | KB5051987 | 26100.3194 | Security |
| Feb D | KB5052093 | 26100.3323 | Preview |
| Mar B | KB5053598 | 26100.3476 | Security |
| Mar D | KB5053656 | 26100.3624 | Preview |
| Apr B | KB5055523 | 26100.3775 | Security |
| Apr D | KB5055627 | 26100.3915 | Preview |
| May B | KB5058411 | 26100.4061 | Security |
| May OOB | KB5061977 | 26100.4066 | Emergency correction |
| May D | KB5058499 | 26100.4202 | Preview |
| Jun B | KB5060842 | 26100.4349 | Security |
| Jun OOB | KB5063060 | 26100.4351 | Emergency correction |
| Jun D | KB5060829 | 26100.4484 | Preview |
| Jul B | KB5062553 | 26100.4652 | Security |
| Jul OOB | KB5064489 | 26100.4656 | Emergency correction |
| Jul D | KB5062660 | 26100.4770 | Preview |
| Aug B | KB5063878 | 26100.4946 | Security |
| Aug D | KB5064081 | 26100.5074 | Preview |
| Sep B | KB5065426 | 26100.6584 | Security |
| Sep OOB | KB5068221 | 26100.6588 | Emergency correction |
| Sep D | KB5065789 | 26100.6725 | Preview |
| Oct B | KB5066835 | 26100.6899 | Security |
| Oct OOB | KB5070773 / KB5070881 | 26100.6901/.6905 | Emergency corrections |
| Oct D | KB5067036 | 26100.7019 | Major preview/features |
| Nov B | KB5068861 | 26100.7171 | Security |
| Nov OOB | KB5072359 | 26100.7178 | Emergency correction |
| Nov D | KB5070311 | 26100.7309 | Preview |
| Dec B | KB5072033 | 26100.7462 | Security |
Microsoft's official release table records these as the primary 24H2 cumulative servicing releases.
Windows 11 25H2
Windows 11 25H2 uses the 26200 build family.
The GA build was 26200.6584, released on 30 September 2025.
25H2 enabled several capabilities that had previously been controlled or gradually introduced in 24H2, including AI actions in File Explorer, Click to Do and Agent in Settings on compatible Copilot+ PCs. It also added Wi-Fi 7 enterprise connectivity and enterprise policy support for removing selected preinstalled Store apps.
Initial 25H2 KB Updates
| Period | KB | Build |
|---|---|---|
| Oct 2025 B | KB5066835 | 26200.6899 |
| Oct OOB | KB5070773 | 26200.6901 |
| Oct D | KB5067036 | 26200.7019 |
| Nov B | KB5068861 | 26200.7171 |
| Nov D | KB5070311 | 26200.7309 |
| Dec B | KB5072033 | 26200.7462 |
Windows 11 Updates Released in 2026
2026 is especially important because Microsoft is servicing several Windows 11 branches simultaneously.
Windows 11 24H2 and 25H2 – 2026
| Period | KB | 24H2/25H2 build | Purpose |
|---|---|---|---|
| Jan B | KB5074109 | .7623 | Security baseline |
| Jan OOB | KB5077744 | .7627 | Emergency fix |
| Jan OOB | KB5078127 | .7628 | Additional emergency fix |
| Jan D | KB5074105 | .7705 | Preview |
| Feb B | KB5077181 | .7840 | Security |
| Feb D | KB5077241 | 25H2 .7922 | Preview |
| Mar B | KB5079473 | 25H2 .8037 | Security |
| Mar OOB | KB5085516 | 25H2 .8039 | Emergency fix |
| Mar D | KB5079391 | 25H2 .8116 | Preview |
| May B | KB5089549 | .8457 | Security |
| May D | KB5089573 | .8524 | Preview |
| Jun B | KB5094126 | .8655 | Security |
| Jun D | KB5095093 | .8737 | Preview |
| Jul B | KB5101650 | .8875 | Security |
| Jul OOB | KB5121767 | .8894 | Compatibility correction |
| Jul D | KB5101684 | .8973 | Preview |
| Aug B | KB5121003 | .9168 | Security |
| Aug D | KB5120998 | .9278 | Latest preview as of this article |
Microsoft lists KB5120998, released 27 August 2026, as build 26100.9278 for 24H2 and 26200.9278 for 25H2.
Important KB5121003 – August 2026 Security Update
KB5121003 is the August 2026 security cumulative update for Windows 11 24H2 and 25H2.
One particularly important known issue affects some ARM-based PCs.
Microsoft documents that Teams and the new Outlook for Windows might fail to start or close unexpectedly on affected ARM devices after updates released on or after this update. Updating the Auto Super Resolution Package through Microsoft Store to version 1.0.19.0 or later is Microsoft's documented workaround at the time of writing.
Important KB5101650 – July 2026
KB5101650 was the July 2026 security cumulative update.
Important changes included:
- additional Secure Boot certificate deployment
- fixes for some third-party applications using OLE Automation with Microsoft Office
- networking security hardening
- Recycle Bin fixes
- updated Windows curl security
- stronger Remote Desktop publisher certificate support
- SHA-2 certificate thumbprints for trusted RDP publishers
- beginning the move away from SHA-1
- removal of picture-password enrollment for new configurations
Some Dell PCs using certain Intel Innovation Platform Framework components were temporarily blocked from receiving the update because of compatibility concerns.
Microsoft subsequently provided KB5121767 as an out-of-band resolution for affected devices.
KB5120998 – August 2026 Preview Update
At the time this article was updated, KB5120998 is one of the most significant recent Windows 11 preview updates.
It applies to:
- Windows 11 24H2
- Windows 11 25H2
Resulting builds:
- 24H2 → 26100.9278
- 25H2 → 26200.9278
Major changes include:
File Explorer
File Explorer Home starts faster and is more responsive.
The Recommended section also receives touch-scrolling improvements.
Administrator Protection
Microsoft continues the rollout of Administrator Protection, designed to reduce persistent administrative privilege exposure by providing just-in-time administrative privileges.
Virtual Desktops
Switching between multiple desktops becomes smoother.
Display and Graphics
Microsoft improved reliability of Display Settings and persistence of brightness settings.
Windows Update
Update restart behavior was improved so that computers manually put to sleep can return to sleep after an update finishes.
Windows Update Orchestration Platform
Participating applications can coordinate their own updates with Windows Update.
Post-Quantum Cryptography
ML-KEM can be used as a standalone algorithm for TLS key exchange in addition to previously introduced hybrid groups.
VPN Reliability
Microsoft improved recovery from certain VPN-process problems that could leave processes unresponsive.
WMIC Removed
A major administrative change begins with the August 2026 servicing period:
WMIC is no longer included with Windows 11 24H2 and 25H2.
This affects the legacy wmic.exe command-line utility, not Windows Management Instrumentation itself.
Administrators should migrate scripts to PowerShell/CIM alternatives.
For example, instead of:
wmic bios get serialnumber
use PowerShell:
Get-CimInstance Win32_BIOS | Select-Object SerialNumber
Known Problems with KB5120998
Microsoft currently documents several important issues.
1. Mouse Customization Can Reset
On some non-English Windows installations, customized mouse pointer/cursor settings can revert to defaults.
Microsoft says manually restoring the values might not work because the affected Windows components fail to load those settings correctly.
2. Teams and New Outlook Problems on ARM
Some ARM devices can experience failures when starting:
- Microsoft Teams
- new Outlook for Windows
Classic Outlook, Word and Excel are not listed as affected by this particular problem.
3. Desktop Background May Turn Black
Some PCs can lose desktop personalization settings after installing KB5120998.
Symptoms can include:
- wallpaper replaced with black background
- slideshow settings lost
- other desktop personalization settings affected
Microsoft is working on fixes for these documented issues.
Windows 11 26H1 – A New Branch in 2026
Another important development is Windows 11 version 26H1, using OS Build 28000.
It became available on 10 February 2026.
Microsoft specifically notes that this release is not offered as an in-place update from Windows 11 24H2 or 25H2 on existing devices. Therefore, administrators should not treat 26H1 as simply the automatic successor every 24H2/25H2 PC should immediately install.
Windows 11 26H1 KB History Through August 2026
| Period | KB | Build | Type |
|---|---|---|---|
| Feb B | KB5077179 | 28000.1575 | Security |
| Feb D | KB5077239 | 28000.1643 | Preview |
| Mar B | KB5079466 | 28000.1719 | Security |
| Mar D | KB5079489 | 28000.1764 | Preview |
| Apr B | KB5083768 | 28000.1836 | Security |
| Apr D | KB5083806 | 28000.1896 | Preview |
| May B | KB5089548 | 28000.2113 | Security |
| May D | KB5089570 | 28000.2179 | Preview |
| Jun B | KB5095051 | 28000.2269 | Security |
| Jun D | KB5095091 | 28000.2340 | Preview |
| Jul B | KB5101649 | 28000.2525 | Security |
| Jul D | KB5101681 | 28000.2608 | Preview |
| Aug B | KB5121000 | 28000.2704 | Security |
| Aug D | KB5120996 | 28000.2804 | Preview |
Windows 11 23H2 – Final Servicing Period
Windows 11 23H2 Enterprise/Education remains relevant in 2026 even though consumer editions have already reached end of servicing.
Important 2026 23H2 security releases include:
| Month | KB | Build |
|---|---|---|
| Jan | KB5073455 | 22631.6491 |
| Jan OOB | KB5077797 | 22631.6494 |
| Jan OOB | KB5078132 | 22631.6495 |
| Feb | KB5075941 | 22631.6649 |
| Mar | KB5078883 | 22631.6783 |
| Apr | KB5082052 | 22631.6936 |
| May | KB5087420 | 22631.7079 |
| Jun | KB5093998 | 22631.7219 |
| Jul | KB5099414 | 22631.7376 |
| Aug | KB5120240 | 22631.7517 |
Microsoft's current servicing table lists Enterprise/Education 23H2 support through 10 November 2026.
Important: Why Are There So Many Different Windows 11 KB Numbers?
A PC does not receive every KB listed in this article.
The KB you receive depends on:
- Windows 11 version
- edition
- CPU architecture
- installed components
- device eligibility
- enterprise servicing configuration
- update channel
- whether optional preview updates are enabled
- safeguard holds
- hardware/driver compatibility
For example, a 24H2 PC and a 23H2 PC can receive completely different KB numbers in the same month.
Does the Latest KB Include Older KB Updates?
For normal cumulative Windows updates, yes.
Suppose the servicing sequence is:
KB-A → KB-B → KB-C → KB-D
A newly installed Windows PC normally does not need A, B and C manually installed before D.
The latest cumulative update contains applicable earlier fixes.
Microsoft explicitly describes Windows servicing this way: installing the latest update ensures that previous updates and important security fixes are included.
This is one of the most important concepts for administrators troubleshooting Windows Update.
Security Update vs Preview Update
Monthly Security Update
Normally released on the second Tuesday of the month.
It generally contains:
- security vulnerability fixes
- quality improvements
- previous cumulative fixes
- applicable improvements tested in earlier preview updates
For most users and organizations:
Install these updates.
Preview / D Release
Usually released later in the month.
It commonly contains:
- upcoming fixes
- reliability improvements
- UI changes
- new functionality
- performance improvements
- fixes planned for inclusion in a future security update
For production systems:
Installation is usually optional unless you specifically need one of the fixes.
Should You Uninstall a Problematic KB?
Only when there is a genuine problem and Microsoft or your own testing indicates the update is responsible.
Before uninstalling an update:
- Identify the exact KB.
- Check your Windows version.
- Check the OS build.
- Review Microsoft's known-issues documentation.
- Check whether Microsoft has released an OOB or newer cumulative update.
- Back up important data.
- Prefer installing Microsoft's corrected update instead of permanently blocking security servicing.
Removing security updates can re-expose vulnerabilities.
How to Check Which Windows 11 KB Updates Are Installed
Open:
Settings → Windows Update → Update history
You can see categories such as:
- Quality Updates
- Driver Updates
- Definition Updates
- Other Updates
You can also use PowerShell:
Get-HotFix
To search for a particular KB:
Get-HotFix -Id KB5121003
Not every modern Windows servicing component is necessarily represented by Get-HotFix, so Settings, DISM and servicing-package information can provide additional detail.
Check Windows Version and Build
Press:
Windows + R
Enter:
winver
You might see something similar to:
Version 25H2 (OS Build 26200.9278)
This information is often more useful than saying only "Windows 11."
When troubleshooting an update, always record:
Windows version + OS build + KB number
Check Installed Packages with DISM
Open Command Prompt as Administrator and run:
DISM /Online /Get-Packages
To filter output for KB packages:
DISM /Online /Get-Packages | findstr KB
DISM can reveal servicing packages that may not appear exactly as expected through older update-query methods.
Can You Manually Download a Windows KB?
Yes.
Microsoft provides standalone packages through the Microsoft Update Catalog.
Before downloading, verify:
- KB number
- Windows version
- architecture: x64 or ARM64
- package applicability
Do not install a package simply because its KB number looks newer.
A package intended for another Windows build might not apply to your computer.
Why a KB May Not Appear on Your PC
Common reasons include:
Wrong Windows version
A 23H2 KB may not apply to 24H2.
Update already superseded
A newer cumulative update might already contain it.
Update not applicable
Your hardware, architecture or Windows configuration may not require the package.
Preview update
Optional previews might not install automatically.
Safeguard hold
Microsoft can temporarily prevent an update or feature release from reaching devices with known compatibility problems.
Enterprise policy
WSUS, Windows Update for Business, Intune or Group Policy may control deployment.
Historical Windows 11 Build Families at a Glance
| Version | Build family | General period |
|---|---|---|
| Windows 11 21H2 | 22000.x | 2021 onward; now legacy |
| Windows 11 22H2 | 22621.x | 2022 onward; now end of updates |
| Windows 11 23H2 | 22631.x | 2023 onward |
| Windows 11 24H2 | 26100.x | 2024 onward |
| Windows 11 25H2 | 26200.x | 2025 onward |
| Windows 11 26H1 | 28000.x | 2026 onward |
Microsoft's current release-information page should always be treated as the authoritative reference for the newest build and KB because the table changes whenever a new cumulative, preview or out-of-band update is released.
FAQ
What was the first Windows 11 cumulative KB update?
The first regular cumulative security update after Windows 11's general availability was KB5006674, released on 12 October 2021, which brought the original Windows 11 branch to build 22000.258.
What is the latest Windows 11 KB as of 7 September 2026?
For Windows 11 24H2/25H2, the latest general cumulative release documented before this article's publication date is the 27 August 2026 preview KB5120998, resulting in builds 26100.9278 and 26200.9278.
The corresponding August security update was KB5121003, released on 11 August 2026.
For Windows 11 26H1, the corresponding August preview is KB5120996, build 28000.2804.
Is KB5120998 a mandatory security update?
No. KB5120998 is a non-security preview cumulative update. It contains production-quality fixes and feature improvements, but it is not the regular monthly security release.
Do I have to install every KB since 2021?
No. Windows cumulative updates contain applicable fixes from earlier cumulative releases.
Why do Windows 11 24H2 and 25H2 sometimes have the same KB?
The two versions share substantial servicing content. Microsoft can therefore publish one cumulative package/KB while producing different OS build numbers for each Windows version.
Why does Windows 11 23H2 use build 22631 while 22H2 uses 22621?
23H2 was built on the same servicing foundation and was enabled through an enablement package, which changed the build family from 22621 to 22631.
What is KB5027397?
KB5027397 is the enablement package used to activate Windows 11 version 23H2 on eligible 22H2 systems.
What does OOB mean?
Out-of-band. It is an update Microsoft releases outside its normal monthly schedule, generally because a problem needs a faster correction.
Should I install Windows preview KB updates?
For ordinary production PCs, they are usually unnecessary unless you need a particular fix or intentionally want early access to the improvements. Regular monthly security updates should receive higher priority.
Can a Windows KB cause problems?
Yes. Even thoroughly tested cumulative updates can expose compatibility problems involving particular drivers, applications, languages, configurations or hardware. Microsoft therefore maintains known-issue and release-health documentation.
Can I uninstall a Windows KB?
Some cumulative updates can be uninstalled through Windows Update's recovery/uninstall options, but removal should generally be a troubleshooting measure rather than a normal practice.
How do I find the KB responsible for a problem?
Record:
- Windows version
- OS build
- installation date
- recently installed KB
- error message or symptom
Then compare the timing of the problem with Microsoft's update release notes and known issues.
Is WMIC removed because of a KB?
Microsoft has been deprecating WMIC for years. Beginning with the August 2026 servicing period for Windows 11 24H2/25H2, the WMIC command-line utility is no longer included/available as before. WMI itself remains supported.
What is the difference between KB number and OS build?
The KB number identifies the update, while the OS build identifies the resulting Windows operating-system revision.
For example:
KB5120998 → Windows 11 25H2 → OS Build 26200.9278
Where should administrators verify the newest Windows 11 KB?
Use Microsoft's official Windows 11 Release Information, Windows Update History, Windows Release Health, and Microsoft Update Catalog resources.
FINAL RECOMMENDATION / CONCLUSION
Windows 11's update history is much easier to understand when KB numbers are viewed together with the Windows version and OS build.
Do not identify a Windows installation only as "Windows 11."
For troubleshooting and support, record it as something similar to:
Windows 11 25H2 – Build 26200.9278 – KB5120998
That immediately tells an administrator which Windows servicing branch and cumulative update is installed.
For normal business and home PCs, prioritize Microsoft's regular monthly security cumulative updates. Treat Preview/D releases as optional, unless they contain a fix you specifically require. Treat OOB updates as important corrective releases and review their applicability when Microsoft publishes one for a problem affecting your environment.
Most importantly, you do not need to install every KB in this historical list. Windows cumulative servicing means that the latest applicable cumulative update normally incorporates fixes from previous cumulative updates.
Because Microsoft continuously revises Windows servicing information, this article should be periodically updated whenever a new monthly Windows 11 cumulative update is released.
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