Cant update from 26H2

Question

Cant update from 26H2

Math 25

Hello,
Im currently on version 26H2 (26300.8935) i was on insider program but i leaved it.

When I boot my windows, it shows me a message telling me to update.

The update tryed is 25H2, a previous version, and it fail every time with the message

The installation failed in the safe_os phase with an error during the operator startup.

I updated all my drivers. Nothing more.

How do I have to proceed ?

Best regards,
Matheo

0 comments

Answer accepted by question author

CrazyKats 17,690 Volunteer Moderator

Great Math,

Something we did corrected something,

with Windows you never know.

Math 25 Reputation points

2026-08-05T17:53:44.3466667+00:00

I guess it's the fact that i checked "Receive the latest updates as soon as they become available." then restarted PC.
Math 25 Reputation points

2026-08-05T18:44:08.28+00:00

I dont have the warning anymore and i'm currently on the version you told me I should be.
Thank you very mutch for your help and time
Bye
CrazyKats 17,690 Reputation points Volunteer Moderator

2026-08-05T18:58:28.7+00:00

Awesome!!!!

7 additional answers

Your answer

Math 25 Reputation points

2026-08-05T17:53:44.3466667+00:00

I guess it's the fact that i checked "Receive the latest updates as soon as they become available." then restarted PC.
Math 25 Reputation points

2026-08-05T18:44:08.28+00:00

I dont have the warning anymore and i'm currently on the version you told me I should be.
Thank you very mutch for your help and time
Bye
CrazyKats 17,690 Reputation points Volunteer Moderator

2026-08-05T18:58:28.7+00:00

Awesome!!!!

Answer 1

CrazyKats 17,690 Volunteer Moderator

Hi Math,

You are on an Insider Dev build.

I would relink your Microsoft Acct.

to the Insider program.

Your Insider settings need to

look like this:

User's image

Your 26300.8935 should be 26300.9032.

Math 25 Reputation points

2026-08-04T13:38:36.6466667+00:00

Hi CrazyKats,

Thanks for your quick answer !
I did what you told me, but after checking both select buttons, nothing happen.
I restarted my PC and I dont have the message on the bottom right of my screen.
But when I launch winver in the execut tool, I'm still on 26300.8935 version.

More info :
In the **Windows Update **> Program windows insider there is a message saying that I have to enable optional diagnostic data. When i click on "Désactivé" to enable it, it automatically switch back to "disabled".
Do you know why ?

Answer 2

CrazyKats 17,690 Volunteer Moderator

Hi Math,

I don't understand why you are being

offered a lower build.

Did you relink your Microsoft account?

At this point I would pause updates

and then wait until builds are released this week.

Math 25 Reputation points

2026-08-05T07:09:10.4133333+00:00

Hi CrazyKats,

I did not relinked my account since it was already logged in, should i try to logout then log back ?

The warning popup says that i have to update before 11 august 2026, do you know when the next build will be released ?

Thanks

Answer 3

CrazyKats 17,690 Volunteer Moderator

You can try that option and see if

it updates and then the settings

might change so you see the 26H2

option as shown in my image.

Or delete this Registry Key and see

what the options show after that.

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsSelfHost

Math 25 Reputation points

2026-08-04T19:26:37.43+00:00

I tryed to select Windows 11, version 26H1 but nothing happened, same with Futures plateformes

I already have nothing in this registry HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\WindowsSelfHost except :

Name : (by default)
Type : REG_SZ Data : (value undefined)

I tryed to reboot, but nothing more. I still have the alert.

Is it normal since i'm in 26H2 and all the version i could take are downgrade ?

Answer 4

CrazyKats 17,690 Volunteer Moderator

Hi Math,

See if any of the Answers in this

thread help:

https://learn.microsoft.com/en-us/answers/questions/5942471/cannot-enable-the-sending-of-optional-diagnostic-d

Math 25 Reputation points

2026-08-04T15:29:41.5433333+00:00

Hi CrazyKats,
Yes it solved the fact that im now sharing optional diagnostic data.
But i still have the popup telling me to update and, has you can see in the screenshot bellow, i'm still on version 26300.8935Do i have to select version 26H1, in the advanced options ?