Hi,

There will be impact to the SQL Server when a domain name is changed, you'll have to see the steps below to get back SQL to the new domain.

1. All Logins must be re-added back to the sql server with same global level permission and user level permissions on each databases.

2. Ensure you have at least one SQL account that has sysadmin access so you would have to enough permissions to add back the users.

3. Update the SQL Server's service account to the new domainname\user for all services logon from SQL Server Configuration Manager.

4. If Replication or Logshipping used then you must ensure the shared folders have the same permissions since you'd have to re-add the users.

5. If linked servers then you need to reconfigure them with new credentials.

Regards,