unable to install the synchronization service. Localdb powershell operation failed on ADSync Bootstrap service. Enable-ADSyncBootStrapLocalDBInstance.

Hello Germain, Frédéric,

Welcome to the Microsoft Q&A and thank you for posting your questions here.

I understand that you are having issues with your installation of Microsoft Azure Active Directory Connect, unable to complete the installation of the synchronization service.

Regarding the information you provided, the contents of the log file specified in the error statement is most needed and this is a similar question on Microsoft Q&A. However, to resolve the ADSync installation issue start with the steps below:

Cat1:

1. Review the Application and System event logs for detailed error messages related to the ADSync installation
2. Fix Azure AD Connect Sync Service not running. https://www.alitajran.com/azure-ad-connect-sync-service-not-running

Cat2:

1. If above not resolve: Remove Corrupt Installation https://support.microsoft.com/en-us/topic/fix-problems-that-block-programs-from-being-installed-or-removed-3c0e7a13-9077-4a6e-8baa-8aa1c2b5b2cb
2. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Classes\Installer\Products by delete it, you'll clean up the Registry. https://video2.skills-academy.com/en-us/answers/questions/1317206/unable-to-install-the-synchronization-service-when
3. After the above 1 & 2 steps, download the latest version of Azure AD Connect from the official Microsoft site https://www.microsoft.com/en-us/download/details.aspx?id=47594 and run the installer.

Everything you be fine. Try to check your Application Service Status.

I hope this is helpful! Do not hesitate to let me know if you have any other questions.

** Please don't forget to close up the thread here by upvoting and accept it as an answer if it is helpful ** so that others in the community facing similar issues can easily find the solution.

Best Regards,

Sina Salam