update to 26H2 from 25H2

Question

update to 26H2 from 25H2

Nidra ZABCI 0

I have windows 11 Pro versionn 25H2 (OS build 26200.8973) . Windows update warned there were updates to be installed. Failed. And there was a blue screen with bitlocker warning. I went to another PC and found the key and entered and restarted my win 11 pro that's when I saw the failed updates :

2026-10 Security Update (KB5127648) (26200.9711) Install error - 0x800f0845

2026-10 .NET Framework Security Update (KB5127690) Install error - 0x800f0845

I didnt retry cause I didnt want to get the Bit Locker problem again.

Then I checked for an annswer and realized that there was an actual 26H2 update, but I want to make sure how to do that since it doesnt show up in my Windows Update. I hope this was clear enough.

Neil D 34,920 Reputation points Volunteer Moderator

2026-10-17T13:17:05.9466667+00:00

If it doesn't show in windows update then you should wait. The device may not be ready for it yet.

So see if you can select one of the updates you mention to install rather than both trying at the same time.

1 answer

Your answer

Neil D 34,920 Reputation points Volunteer Moderator

2026-10-17T13:17:05.9466667+00:00

If it doesn't show in windows update then you should wait. The device may not be ready for it yet.

So see if you can select one of the updates you mention to install rather than both trying at the same time.

Answer 1

Windows 11, version 26H2 is delivered as a phased rollout to eligible devices running 25H2 or 24H2. If it does not appear in Settings > Windows Update, that usually means the device is not yet being offered the update, or a safeguard hold is in place.

What is supported:

Go to Settings > Windows Update.
Turn on Get the latest updates as soon as they’re available.
Check whether Windows 11, version 26H2 appears with Download & install.
If it appears, install it there. For eligible 25H2 devices, the update uses servicing technology and completes with a single restart.

Important details for this upgrade:

Windows 11 versions 24H2, 25H2, and 26H2 share the same core operating system and identical system files.
The 26H2 features are already present in a dormant state and are turned on by a small enablement package.
For devices that receive updates directly from Windows Update or WSUS, the enablement package is delivered automatically when the feature update is offered.

Because 26H2 is not showing yet, the next step is to wait until the rollout reaches the device or any safeguard hold is removed. Microsoft states that availability expands over time and that safeguard holds can block the offer when a known compatibility issue is detected.

For the earlier failed updates and restart concern:

If Windows reports that a restart is required before setup can continue, the documented first step is to restart the PC.
If the same condition repeats after two or three restarts, reinstalling recently installed programs or Windows updates is the next documented step.
Do not try to work around restart/update issues by manually editing or deleting Windows Registry keys. That can cause further problems.

If immediate help is needed for the Windows Update failures, use the Get Help app from Windows or go to support.microsoft.com.