What are folks using for a windows based free radius server? I’d appreciate any suggestions that work well with Mikrotik.
i would not sound arrogant but - windows ans security???
if you cannot find one then install wmvare virtual server - set there linux and install simple linux radius server.
Yeah I know…but we have and existing windows server that can handle the load so we don’t want to invest in another server for linux (have to factor in power, UPS, etc, costs also).
freeradius has an windows version. I haven’t tried it and was going to ask here first.
i clearly understand that, thats why i suggested if you cannot find any free RADIUS implementation you can use VIRTUAL server from vmware and install there linux and freeRADIUS.
vmware now is free of use if unless you want support.
that could be a solution for you.
and now back to ROS and RB 
Thanks
Can you run router OS in a VM? 
There’s also Microsoft IAS (Internet Authentication Services) which is Microsoft’s idea of Radius… Never used it though, don’t intend on using it either…
Yes, the whole idea of VMWare is to run Virtual OSes on a Host OS…
You can try https://www.kaplansoft.com/tekradius/
There is generally no need to install a third party RADIUS server (free or commercial). Windows Server has RADIUS built-in as part of the Network Policy and Access Services role. Use Server Manager to add this role to a server in your Active Directory domain. No additional licensing is required.
Here is a page that walks you through the process of setting it up (including configuring a MikroTik router as a RADIUS client using Winbox3):
https://theitbros.com/radius-server-configuration-on-windows/
Did we really just get an ad on an 18-year-old post? 
It looks like that. That user @internetworker only had two posts, both resurrecting 18 y.o. threads to mention that RADIUS software. And that other account with the AI post content has just been created.