What versions of Windows are supported?

I hope this isn’t an unwelcome detour on this thread. I recently moved a big community from VBulletin to Discourse and discovered some Windows 7 users that couldn’t access the site. I found the posts here and I mentioned Thorium to the user who was having trouble. He has installed it, it works, and he’s using our Discourse now.

My question is: I don’t know what people see when their browser isn’t supported (assuming the TLS is negotiated correctly, but the browser lacks the required capabilities) I don’t know how to control the text on that screen. On my Discourse, can I put links to things like Thorium on the page they see when their browser isn’t supported? Based on what they said, it sounds like this user was seeing something but it was a landing page or error page telling him that his browser wasn’t supported.

Is the text that users see in this situation something I can control as an admin? Discourse might not want to put a link to some random project like Thorium in the default install. But I’m perfectly willing to do it on my own site. I just don’t know where it is.

Related, is there a way I can, with a modern computer and modern browsers, tweak my setup somehow so I can see what my users are seeing in these situations? I don’t have any Windows 7 or ancient devices available to me. I know what it looks like if TLS fails to negotiate, and that’s not a thing I can fix, but what if TLS does succeed but the browser is too old? How do I see that?