The Security Center was made not only to register antiviruses, but also to register firewalls, too. These are two fundamental components of protection. SpyShelter Firewall already in its name positions itself as a firewall, and not as a hips or sandbox, although hips is its main “trick”, but the firewall is also its integral part. Any number of third-party software can be installed, but it would be best to register with the Security Center so that the fundamental security programs, such as anti-virus and firewall, so that the user is not afraid of warnings from the system about the vulnerability.Security Center was made for AVs, not alternative mechanism like HIPS or Sandboxes, so SpS not registering in it isn't big deal. All my favorite 3rd party softs don't register, and I won't care anyway if they do or not.