Win11 update from Win10 -- Error Code: 0xC1900101 0x40021 The installation failed in the SECOND_BOOT phase with an error during SYSPREP_RESPECIALIZE operation

Hi Team,

I keep getting win 11 update failure from win 10. The system auto update and `Windows11InstallationAssistant` doesn't work for me. Recently, I download the ISO and it shows the error message after another update failure

```

0xC1900101 0x40021 The installation failed in the SECOND_BOOT phase with an error during SYSPREP_RESPECIALIZE operation

```

Here is the Open the "Panther" and "Rollback" folder in "C:\$WINDOWS.~BT\Sources\" folder:

Panther.zip

Rollback.zip

Can someone help me?

Best,

Bill

Answer
Answer

Hi Bill,

Please open admin Command Prompt and run these commands:

  • reg export "HKLM\SYSTEM\CurrentControlSet\Services\RECentralService" C:\RECentralService.reg

  • sc.exe delete RECentralService

Now, attempt to upgrade to Windows 11.

______________________________________________________________________________________________________
Ramesh, Windows Shell MVP 2003-2012.
If this post resolves your issue, pls mark it as an Answer.

1 person found this reply helpful

·

Was this reply helpful?

Sorry this didn't help.

Great! Thanks for your feedback.

How satisfied are you with this reply?

Thanks for your feedback, it helps us improve the site.

How satisfied are you with this reply?

Thanks for your feedback.

 
 

Question Info


Last updated April 17, 2025 Views 86 Applies to: