Win Update KB5129195 Windows 11 Out-of-band Cumulative Update build 26100.9457 (24H2), 26200.9457 (25H2), and 26300.9457 (26H2) - Sept. 14



 Microsoft Support:

This out-of-band (OOB) update for Windows 11, version 25H2 and Windows 11, version 24H2 (KB5129195) is cumulative. It includes updates from previous releases, along with additional security and non-security improvements. Visit the Windows release health dashboard for the latest status on this release.

Improvements​

This OOB update includes the following improvement:
  • [Security] This update includes protections documented in CVE-2026-62721, which refers to a Windows User-Mode Power Service (UMPS) Elevation of Privilege vulnerability.
  • [Remote Desktop Services (known issue)] Fixed: This update addresses an issue affecting Remote Desktop Services (RDS) after installing the September 2026 Windows security update (KB5122880). In affected environments, RDS might become unstable, causing RDP connection and sign-in failures or servers to become unresponsive during Remote Desktop configuration. Related tools, including Microsoft Management Console (MMC), RDS Licensing Diagnoser, File Explorer, and the Windows Update page, might also stop responding.
  • [Hyper-V (known issue)] Fixed: Some applications that use HCS-managed virtual machines experienced issues when sharing host folder with Linux VMs using Plan9. Folders shared from the Windows host using Plan9 did not appear or could not be accessed in the guest environment.
  • [8-channel or 3D audio modes] Fixed: Some USB Audio Class 1.0 devices functioning as expected in standard stereo configurations failed when using multichannel audio features, including 8-channel or 3D audio modes. (Note: There are other audio symptoms not resolved in this OOB update. See the “Known issues in this update” section for more information.)

Component updates​

Windows 11 servicing stack update (KB5124007) - 22621.9441​

This update makes quality improvements to the servicing stack, which is the component that installs Windows updates. Servicing stack updates (SSU) ensure that you have a robust and reliable servicing stack so that your devices can receive and install Microsoft updates. To learn more about SSUs, see Simplifying on-premises deployment of servicing stack updates.

Known issues in this update​

Symptoms

After installing the September 8, 2026, Windows security update, some USB Audio Class 1.0 devices might fail to start or produce audio. Affected devices might experience one or more of the following symptoms: The device displays an error in Device Manager: "This device cannot start (Code 10).” No audio output. Volume controls are unresponsive or remain at zero. Sound settings are unresponsive or unavailable. This issue is limited to USB Audio Class 1.0 devices.

Resolution
Microsoft is working on a resolution and will update this documentation when more information is available.

How to get this update​

Before you install this update

Microsoft now combines the latest servicing stack update (SSU) for your operating system with the latest cumulative update (LCU). For general information about SSUs, see Servicing stack updates and Servicing Stack Updates (SSU): Frequently Asked Questions.

Install this update

To install this update, use one of the following Windows and Microsoft release channels.

Available​
Next Step​
Available
This update downloads and installs automatically from Windows Update and Microsoft Update.
Available
To install this update, download the standalone package(s) for this update from the Microsoft Update Catalog. This update contains MSU files that require installation in a specific order. Follow the Arm64 installation instructions or x64 installation instructions, as appropriate.

If you install additional Dynamic Update packages, use versions from the same release month as this update. If a Safe OS Dynamic Update or Setup Dynamic Update is not available for the same release month, use the most recently released version.

Note This latest cumulative update includes updates for AI components. AI components are applicable only to Copilot+ PCs and will not install on other Windows client PCs or Windows Server.

File Information

For a list of the files provided in this update, download the file information for cumulative update KB5129195.

For a list of the files provided in the servicing stack update, download the file information for SSU KB5124007 - versions 22621.9441.


 Source:

September 14, 2026—KB5129195 (OS Builds 26200.9457 and 26100.9457) Out-of-band | Microsoft Support

September 14, 2026—KB5129195 (OS Builds 26200.9457 and 26100.9457) Out-of-band
support.microsoft.com support.microsoft.com


Check Windows Updates


ISO from Microsoft MCT:

www.elevenforum.com

Download Official Windows 11 ISO file from Microsoft

This tutorial will show you how to download an official Windows Server or Windows 11 64-bit or ARM64 ISO file from Microsoft. Microsoft provides ISO files for Windows Server and Windows 11 to download. You can use these ISO files to clean install or in-place upgrade Windows 11. The Flight Hub...
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UUP Dump:

64-bit ISO download:
uupdump.net

Select language for Windows 11, version 24H2 (26100.9457) amd64

Select language for Windows 11, version 24H2 (26100.9457) amd64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
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uupdump.net

Select language for Windows 11, version 25H2 (26200.9457) amd64

Select language for Windows 11, version 25H2 (26200.9457) amd64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
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uupdump.net

Select language for Windows 11, version 26H2 (26300.9457) amd64

Select language for Windows 11, version 26H2 (26300.9457) amd64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net

ARM64 ISO download:
uupdump.net

Select language for Windows 11, version 24H2 (26100.9457) arm64

Select language for Windows 11, version 24H2 (26100.9457) arm64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net
uupdump.net

Select language for Windows 11, version 25H2 (26200.9457) arm64

Select language for Windows 11, version 25H2 (26200.9457) arm64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net
uupdump.net

Select language for Windows 11, version 26H2 (26300.9457) arm64

Select language for Windows 11, version 26H2 (26300.9457) arm64 on UUP dump. UUP dump lets you download Unified Update Platform files, like Windows Insider updates, directly from Windows Update.
uupdump.net

www.elevenforum.com

UUP Dump - Download Windows Insider ISO

UUP Dump is the most practical and easy way to get ISO images of any Insider Windows 10 or Windows 11 version, as soon as Microsoft has released a new build. UUP Dump creates a download configuration file according to your choices, downloads necessary files directly from Microsoft servers, and...
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Last edited:
Click to expand...
garlin said:
@Brink MCT ISO has updated to 26200.9457
Click to expand...
@garlin,
Could you please point to your latest Repair_My_BootWIM.ps1 and the command syntax to fix the boot.wim on the installation media created by MCT 26200.9457.
The last one I have did not work and I had to download from UUP-dump.
Thanks.

1789510811751.webp
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2Intel I9-9900K64GBNVIDIA RTX 2060
OS
Windows 11 Pro 25H2
Computer type
PC/Desktop
Manufacturer/Model
Dell XPS 8930
CPU
Intel I9-9900K
Memory
64GB
Graphics Card(s)
NVIDIA RTX 2060
Sound Card
NVIDIA High Definition Audio
Monitor(s) Displays
4k Samsung
Screen Resolution
3840 x 2160
Hard Drives
512GB NVMe, ADATA SU 800, 2TB HDD
Here's the current version, you provide a drive letter (of the mounted USB) to the script.
Code: 
powershell -ep bypass -f Repair_My_BootWIM.ps1 D:
 

My Computer My Computer

At a glance

Windows 7
OS
Windows 7
garlin said:
Here's the current version, you provide a drive letter (of the mounted USB) to the script.
Code: 
powershell -ep bypass -f Repair_My_BootWIM.ps1 D:
Click to expand...
Thanks,
I'll try it out. 🤞
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2Intel I9-9900K64GBNVIDIA RTX 2060
OS
Windows 11 Pro 25H2
Computer type
PC/Desktop
Manufacturer/Model
Dell XPS 8930
CPU
Intel I9-9900K
Memory
64GB
Graphics Card(s)
NVIDIA RTX 2060
Sound Card
NVIDIA High Definition Audio
Monitor(s) Displays
4k Samsung
Screen Resolution
3840 x 2160
Hard Drives
512GB NVMe, ADATA SU 800, 2TB HDD
Hi everyone,

I installed the update and experienced a few issues right after, although everything seems fine now. I’m still a bit concerned and curious if others had similar problems.

Here’s what happened:

  • During boot, before the MSI motherboard logo appears, I got a black screen with a small white line in the top-left corner (like a terminal cursor). It lasted longer than usual.
  • On the login screen, I had a long freeze when entering my PIN. Also, instead of the usual rotating Windows background, my personal desktop wallpaper was displayed.
  • My wireless Logitech headset was no longer recognized (USB dongle). Even after several reboots, it didn’t work. I fixed it by plugging the USB receiver into a different port.
Everything is working normally now, but the behavior right after the update was a bit worrying.

Has anyone experienced something similar with this update?
 

My Computer My Computer

At a glance

windows 11
OS
windows 11
garlin said:
Here's the current version, you provide a drive letter (of the mounted USB) to the script.
Code: 
powershell -ep bypass -f Repair_My_BootWIM.ps1 D:
Click to expand...
@garlin,
Where is PITRestore.exe?

I got this:

1789515730434.webp
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2Intel I9-9900K64GBNVIDIA RTX 2060
OS
Windows 11 Pro 25H2
Computer type
PC/Desktop
Manufacturer/Model
Dell XPS 8930
CPU
Intel I9-9900K
Memory
64GB
Graphics Card(s)
NVIDIA RTX 2060
Sound Card
NVIDIA High Definition Audio
Monitor(s) Displays
4k Samsung
Screen Resolution
3840 x 2160
Hard Drives
512GB NVMe, ADATA SU 800, 2TB HDD
There was some talk about USB issues recently, maybe that's what you're seeing? I haven't personally seen any USB problems, but I'm only a sample of one.
 

My Computers My Computers

System One System Two Other systems

  • At a glance

    Win 11 Pro 25H2, Build 26200.9457Intel Core i5 14500, 14th Generation64GB DDR4GeForce RTX 4060
    OS
    Win 11 Pro 25H2, Build 26200.9457
    Computer type
    PC/Desktop
    Manufacturer/Model
    Home Brew
    CPU
    Intel Core i5 14500, 14th Generation
    Motherboard
    Gigabyte B760M G P WIFI
    Memory
    64GB DDR4
    Graphics Card(s)
    GeForce RTX 4060
    Sound Card
    Chipset Realtek
    Monitor(s) Displays
    LG 45" Ultragear & Acer 24" 1080p
    Screen Resolution
    5120x1440 & 1920x1080
    Hard Drives
    Crucial P310 2TB 2280 PCIe Gen4 3D NAND NVMe M.2 SSD (O/S)
    Silicon Power 2TB US75 NVMe PCIe Gen4 M.2 2280 SSD (backup)
    Crucial BX500 2TB 3D NAND (2nd backup)
    Seagate 4TB Ironwolf, rotating HDD secondary backup
    External off-line backup Drives: 2 NVMe 4TB drives in external enclosures
    PSU
    Thermaltake Toughpower GF3 750W
    Case
    LIAN LI LANCOOL 216 E-ATX PC Case
    Cooling
    Lots of fans!
    Keyboard
    Microsoft Comfort Curve 2000
    Mouse
    Logitech G305
    Internet Speed
    Verizon FiOS 1GB
    Browser
    Firefox
    Antivirus
    Malware Bytes & Windows Defender Security

  • At a glance

    Win 11 Pro 25H2, Build 26200.9168Intel Core i5 1440032GB DDR5Intel 700 Embedded GPU
    Operating System
    Win 11 Pro 25H2, Build 26200.9168
    Computer type
    PC/Desktop
    Manufacturer/Model
    Home Brew
    CPU
    Intel Core i5 14400
    Motherboard
    Gigabyte B760M DS3H AX
    Memory
    32GB DDR5
    Graphics card(s)
    Intel 700 Embedded GPU
    Sound Card
    Realtek Embedded
    Monitor(s) Displays
    27" HP 1080p
    Screen Resolution
    1920x1080
    Hard Drives
    Crucial P310 2TB NVMe Gen4 SSD
    Samsung EVO 990 2TB NVMe Gen4 SSD
    Samsung 2TB SATA SSD
    Seagate 4TB Ironwolf, rotating HDD secondary backup
    PSU
    Thermaltake Smart BM3 650W
    Case
    Okinos Micro ATX Case
    Cooling
    Fans
    Keyboard
    Microsoft Comfort Curve 2000
    Mouse
    Logitech G305
    Internet Speed
    Verizon FiOS 1GB
    Browser
    Firefox
    Antivirus
    Malware Bytes & Windows Defender Security
  • Nimo N171 17" Laptop, (Intel i3-1215U, 16GB RAM, 2TB NVMe, Win11 Pro)
    Acemagic Vista Mini PC V1 (Intel N150, 16GB RAM, 1TB NVMe, Win11 Pro)
    HP ENVY h8-1540t, (24GB RAM, 2TB SSD, 2TB HDD, Win11 Pro)
gunrunnerjohn said:
There was some talk about USB issues recently, maybe that's what you're seeing? I haven't personally seen any USB problems, but I'm only a sample of one.
Click to expand...
I don't have any problems with USB. 🤷‍♂️
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2Intel I9-9900K64GBNVIDIA RTX 2060
OS
Windows 11 Pro 25H2
Computer type
PC/Desktop
Manufacturer/Model
Dell XPS 8930
CPU
Intel I9-9900K
Memory
64GB
Graphics Card(s)
NVIDIA RTX 2060
Sound Card
NVIDIA High Definition Audio
Monitor(s) Displays
4k Samsung
Screen Resolution
3840 x 2160
Hard Drives
512GB NVMe, ADATA SU 800, 2TB HDD
garlin said:
Oops, my bad. Gave you a copy of a test version where I was trying to hack PITR into boot.wim.
This should be the one without PITR involved.
Click to expand...
This worked, I'll boot and see if it fixed the problem. Back in a few minutes. Thanks.

Edit:
"Repair my PC" worked fine thanks again. 👍

1789517031467.webp
 

My Computer My Computer

At a glance

Windows 11 Pro 25H2Intel I9-9900K64GBNVIDIA RTX 2060
OS
Windows 11 Pro 25H2
Computer type
PC/Desktop
Manufacturer/Model
Dell XPS 8930
CPU
Intel I9-9900K
Memory
64GB
Graphics Card(s)
NVIDIA RTX 2060
Sound Card
NVIDIA High Definition Audio
Monitor(s) Displays
4k Samsung
Screen Resolution
3840 x 2160
Hard Drives
512GB NVMe, ADATA SU 800, 2TB HDD
The update broke File History on my HP Laptop as reported by others. This is typical shoddy MS software engineering so its prudent to wait before updating.
 

My Computer My Computer

At a glance

Windows 11 ProCore i7-13700K64 GB Kingston Fury Beast DDR5Gigabyte GeForce RTX 2060 Super Gaming OC 8G
OS
Windows 11 Pro
Computer type
PC/Desktop
Manufacturer/Model
Self build
CPU
Core i7-13700K
Motherboard
Asus TUF Gaming Plus WiFi Z790
Memory
64 GB Kingston Fury Beast DDR5
Graphics Card(s)
Gigabyte GeForce RTX 2060 Super Gaming OC 8G
Sound Card
Realtek S1200A
Monitor(s) Displays
Viewsonic VP2770 & Dell (secondary)
Screen Resolution
2560 x 1440
Hard Drives
Kingston KC3000 2TB NVME SSD & SATA HDDs & SSD
PSU
EVGA SuperNova G2 850W
Case
Nanoxia Deep Silence 1
Cooling
Noctua NH-D14
Keyboard
Microsoft Digital Media Pro
Mouse
Logitech Wireless
Internet Speed
80 Mb / s
Browser
Chrome
Antivirus
Defender, Malwarebytes Free & AdwCleaner
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