If Windows 11 version 25H2 fails to install then the best solution is to run the following software:
1: Windows 11 PC Health Checker – Download and Run – This is a requirement for the Windows 11 Installation Assistant 25H2 to check compatibility.
https://go.microsoft.com/fwlink/?linkid=2169346
2: Windows 11 Installation Assistant 25H2 – Download and Run – This will take hours to complete and it will then reboot.
https://www.microsoft.com/en-us/download/details.aspx?id=108398
Hopefully everything works after the reboot but the most likely issue is the Window PIN fails to work.
3: Fix Windows Hello Pin after installing 25H2 – only do this if you can’t set the Windows Hello PIN.
Open a Command Prompt (run as administrator) – Paste each line and press enter – One at a time.
takeown /f C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\Ngc /r /d y
icacls "C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\Ngc" /grant administrators:F /t
rd /s /q C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\Ngc
md C:\Windows\ServiceProfiles\LocalService\AppData\Local\Microsoft\Ngc
