The HZS_System database must reside on the same SQL server as any company databases where the HQMS_ tables are stored.  The datasource in the connection will be the same for the HZS_System database as the company.  If the database is on a different instance the system will try to find it on the server where the config file points to.  It won't be able to see it an errors will occur on login and/or when users try to open any forms in the system and it will deny them access.