No, there is not a Microsoft Windows version of the Interlink Networks, LLC RAD-Series RADIUS server. The RAD-Series RADIUS Server is available for the Solaris OS running on the SPARC architecture and the Linux OS running on the Intel x86 architecture.
Currently, there are no plans to develop a Windows version. It is not on the roadmap.
If you would like to make a case for a Windows version, please submit a feature request.