Can't downgrade to 25H2 or upgrade to 26H2

Hello.

I had (I think) Windows Insider set on Canary or Dev and Windows 11 was on 26300.9032 and it is now 26340.9212.

I was able to move two systems that were on Windows 11 build 26300.x to 26300.9278 with success but somehow the Run dialog lost it's dark mode, maybe because it set the WIP to ReleasePreview.

Back to the system I'm having problems...
The WIP (Settings -> Windows Update -> Windows Insder) has (still has) Release Preview and Beta greyed. I can choose Canary and Dev but I can select Release Preview via reg hack.

I compiled an ISO file with 26300.9278 from uup dump site and tried to install it. The phase inside of Windows goes ok, the PC reboots, starts setup but it restarts and upon reboot, it shows a message it was undoing the changes.
Strangely when 26340 was installed, I didn't have the option to uninstall it. I thought the WU was paused like the other systems.

A thing even more strange happened yesterday: The Windows 11 25H2 setup saying my PC needed TPM 2.0 and my processor couldn't run the Windows version. It is true my system lacks of TPM 2.0 but it has TPM 1.2 and the processor is an i7 3770, which has SSE4.2. The bypass tpm cpu reg hack also didn't work. Things I didn't try yet: replace the dll in sources.

bcdedit has flightsigning set as yes.

I tried deleting a folder that says something-selfhost but when I go to the WIP section in WU, the account comes back again.
I do not want to reinstall Windows.
There must be there a way to move from 26340 to 26200 or to 26300.

Dev channel allows me to install 26340.something, a number higher than .9212.
The Cananry allows me to install 28020 or 296something.
I don't remember quite well, but I think I tried to install 26h1 in the past but it failed.

I thing I also noticed is that dism /online /cleanup-image /scanhealth says component store is repareable, I ran /restorehealth, it completes ok, but /scanhealth again says it can be repared.

I want to un-grey out Release Preview.
Any ideas?

If you are getting option to repair install (in-place upgrade) Windows 11 then you have no problem upgrading except for upgrade not completing.

Thanks for the reply, FreeBooter.
In order to repair the installation (/scanhealth and /restorehealth) I did install 92340.9212 on top of it, using an ISO file.
Even so, at first the /restorehealth couldn't find a source and later did fix it with /source:wim:d:\sources\install.wim:1
Not sure if I want to go higher than 26340.9212 to solve my issue.

I confused of what you are doing are having problem with in-place upgrade.

You can also perform in-place upgrade of Windows 11. In-place upgrade is to use to replace the current operating system files on your computer. Unlike a clean installation of Windows, you can start a Windows in-place upgrade when your OS is still running. And an in-place upgrade can keep your files, settings, & apps during the upgrade process. You can perform a Windows 11 in-place upgrade is to use the Windows 11 Media Creation Tool. Make sure to select Upgrade this PC now and click Next. Follow the on-screen guide to perform a Windows 11 in-place upgrade.



To fix the "source files could not be found" DISM error (Error 0x800f081f), you need to provide the command with a working repair source, such as a mounted Windows installation ISO file.

Download the official Windows ISO file matching your exact operating system version.

Right-click the downloaded ISO file in File Explorer and select Mount.

Note the new drive letter assigned to the mounted drive.


Open Command Prompt or PowerShell as an administrator.

Run this command to see the available image indexes, replacing X with your mounted drive letter:


Note the index number (#) that matches your specific edition of Windows (such as Windows 10 Pro or Windows 11 Home).

Run the repair command with your custom source and limit access to Windows Update, replacing X with the drive letter and # with your index number:


After DISM completes successfully, type the following command and press Enter:


Restart your computer once the scan finished.