"The Microsoft Azure AD Sync service failed to start due to the following error: The service did not start due to a logon failure

Hello @Mark Horca

Thanks for contacting MS Q&A. I will assist you with resolving your issues.

Yes, resetting the password and updating the ADSync service logon credentials is a good next step, especially if the synchronization service is still failing to start even after confirming that:

• The account is not locked out
• It has “Log on as a service” rights
• The password is set to never expire
• The server has been restarted

Recommended Steps:

1. Reset the AD service account password in Active Directory (or if it's a local account, do it in Computer Management).
2. Open Services.msc on the Azure AD Connect server.
3. Locate the service called: Microsoft Azure AD Sync
4. Right-click it → Properties → Log On tab.
5. Re-enter the new password for the service account.
6. Click OK and attempt to start the service again.

Additional Checks (if issue persists):

1. Event Viewer → Application Logs for specific sync or service errors.
2. Confirm if there are GPOs or security settings overriding the logon rights.
3. Run Azure AD Connect Troubleshooter (C:\Program Files\Microsoft Azure AD Sync\Bin\AzureADConnect.exe > Troubleshoot).

If this answers your query, do click Accept Answer and Yes for was this answer helpful. And, if you have any further query do let us know.

Siri