Set strong passwords for the Administrator and any other OS accounts that have any DIVArchive or DIVAdirector administrator or service roles assigned to them.
Do not use a local administrator OS account but rather assign roles as needed to other user accounts.
Set a strong password for the DIVAdirector Administrator user. Change the password right away from the default installed password to a strong password. You can do this from the DIVAdirector Admin, Personal settings screen.
Install a firewall on the system and apply the default DIVAdirector port rules.
Install OS and DIVAdirector updates on a periodic basis since they include security patches.
Install antivirus and exclude the DIVAdirector processes and storage for performance reasons.