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

1. Manually Remove Any Corrupt LocalDB Files

A. Stop Any Running SQL Services

Run the following command in PowerShell (Admin):

Stop-Service "MSSQL$MICROSOFT##SSEE" -Force -ErrorAction SilentlyContinue

Stop-Service "MSSQL$SQLEXPRESS" -Force -ErrorAction SilentlyContinue

Stop-Service "MSSQL$MSSQLSERVER" -Force -ErrorAction SilentlyContinue

Then, check for running instances:

Get-Service | Where-Object {$_.DisplayName -like "SQL" }

If you see any running SQL Server-related services, manually stop them from Task Manager > Services.

B. Delete SQL LocalDB Files Manually

1. Open File Explorer and go to:

2.  C:\Users\dcadmin\AppData\Local\Microsoft\Microsoft SQL Server Local DB\Instances\

1. Delete the entire MSSQLLocalDB folder.
2. Navigate to:

5.  C:\Program Files\Microsoft SQL Server\

and delete any folders related to LocalDB.

2. Remove LocalDB from Registry

Since LocalDB is not functioning properly, we need to clean the registry:

1. Open Registry Editor (regedit.exe).
2. Navigate to:

3.  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server Local DB\Instances\

1. Delete the MSSQLLocalDB key.
2. Navigate to:

6.  HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\

and delete any references to LocalDB.

3. Reinstall LocalDB

A. Uninstall LocalDB Completely

1. Open Control Panel > Programs & Features.
2. Uninstall:
   • Microsoft SQL Server LocalDB
     • Microsoft SQL Server 2019 Express LocalDB (or any other version)
       • Microsoft SQL Server Compact Edition (if installed)

B. Download and Reinstall LocalDB

1. Go to Microsoft's website: Download SQL Server Express LocalDB
2. Download the SQL Server Express LocalDB installer.
3. Install it using the default settings.

4. Recreate and Start LocalDB

After reinstalling, run:

sqllocaldb create MSSQLLocalDB

sqllocaldb start MSSQLLocalDB

sqllocaldb info

You should now see the instance properly created and running.

5. Retry Installing Entra Connect

Once LocalDB is working, retry installing Microsoft Entra Connect.