NSIA requires the free Sun Java Runtime (JRE) version 6 or higher.
Note that the installers will attempt to determine if you have Java installed already.
ThreatFactor is self-contained and can be easily run without running an installation; simply drag it to a directory and run the server to begin.
However, an installer is provided and should be used on Windows if you plan on installing the ThreatFactor server as a Windows service.
ThreatFactor NSIA definitions are free.
Register for an account on ThreatFactor.com then generate a free license key for each of your scanners.
If do not want to register, you can download the definitions and import them manually into NSIA.