Windows Update hangs or fails when trying to install KB5074109 (Windows 11 24H2/25H2) or KB5073455 (Windows 11 23H2) from January 2026 Patch Tuesday. The update downloads, attempts to install, then rolls back on reboot. For the May 2026 KB5089549 failure, see the EFI System Partition section below.

Common error codes:

0x800f0922 - CBS servicing error
0x80070306 - Package installation failure
"Updates failed. Undoing changes."

The Fix

Run DISM and SFC to repair the component store, then retry the update.

Open PowerShell as Administrator and run:

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

After reboot, check for updates again. The install should succeed.

If That Doesn't Work: Reset Windows Update Components

Stop the update services, rename the cache folders, and restart:

net stop wuauserv
net stop cryptSvc
net stop bits
net stop msiserver
ren C:\Windows\SoftwareDistribution SoftwareDistribution.old
ren C:\Windows\System32\catroot2 catroot2.old
net start wuauserv
net start cryptSvc
net start bits
net start msiserver

Reboot and retry Windows Update.

If That Doesn't Work: Install Manually via DISM

Download the update from the Microsoft Update Catalog and install directly:

DISM /Online /Add-Package /PackagePath:C:\Downloads\Windows11.0-KB5074109-x64.msu

Or via PowerShell:

Add-WindowsPackage -Online -PackagePath "C:\Downloads\Windows11.0-KB5074109-x64.msu"

If That Doesn't Work: Check Disk Space and Driver Conflicts

Updates require at least 20GB free on C:. Also check for NVIDIA or storage driver conflicts causing rollback:

# Check free space
Get-PSDrive C | Select-Object Used,Free

# Check recent driver installs
Get-WmiObject Win32_PnPSignedDriver |
    Where-Object {$_.DriverDate -gt (Get-Date).AddDays(-30)} |
    Select-Object DeviceName, DriverVersion, DriverDate

If you have an NVIDIA GPU and experience black screens after update, roll back the GPU driver or update to the latest version before retrying.

Verify

After successful installation, confirm the build number:

winver

Windows 11 24H2 should show build 26100.7623. Windows 11 25H2 should show 26200.7623. Windows 11 23H2 should show 22631.6491.

May 2026: KB5089549 Fails Near 35% on Full EFI Partitions

If you hit 0x800f0922 on the May 2026 update specifically, the cause is different from the January servicing errors above, and so is the fix. KB5089549 is the May 12 cumulative for Windows 11 24H2 and 25H2. On affected machines it downloads, restarts, then stops near 35 percent with the message "Something didn't go as planned. Undoing changes."

Microsoft has confirmed this as a known issue. The trigger is a nearly full EFI System Partition, the small boot partition Windows uses during servicing. Devices with roughly 10MB or less free in that partition are the ones that fail. It shows up most on hardware that ships with a small EFI partition, including some HP EliteBook models and a number of Windows Server 2019, 2022, and 2025 systems.

To confirm you are looking at the same problem, open C:\Windows\Logs\CBS\CBS.log and search for entries about insufficient free space on the EFI System Partition.

First: Restart and Retry

Microsoft is fixing this through Known Issue Rollback. On consumer PCs and unmanaged business devices, the rollback applies on its own once it reaches the machine. Restart the device, return to Windows Update, and run the install again. Many systems succeed on the second or third try.

Managed Fleets: Deploy the KIR Group Policy

Domain-joined and MDM-managed devices won't receive the rollback automatically. An administrator has to deploy the Known Issue Rollback Group Policy for this issue and then reboot the affected machines. Microsoft lists the policy and the affected builds on the Windows release health dashboard.

If Retries Still Fail: Free Up the EFI Partition

When the rollback is in place and the update still rolls back, the EFI System Partition itself is too full to service. Microsoft also published a registry workaround in its official KB5089549 documentation that lowers the padding Windows reserves inside that partition during servicing. Registry edits and changes to the boot partition carry real risk, so take the exact steps from Microsoft's own page and image the machine before you start.

If you'd rather not touch the partition, you can download KB5089549 from the Microsoft Update Catalog and install it manually, though the same space limit can still block it. A permanent fix is expected in a future Windows update, so on most fleets the practical move is to apply the Known Issue Rollback and let retries clear the backlog.

Having update issues across your fleet? Contact us for managed patch deployment.