The only time I've ever used Ruby on Rails was in a cPanel (Linux) server, so I'm wondering if Windows also supports RoR. And if it does, how good is Windows as a platform for Ruby?
Actually, it is possible to install Ruby on Rails in a Windows environment. The Rails Wiki has a page with a guide on how to install Ruby on Rails in Windows.
This is the reason I went with a Linux hosting platform, just so I could be sure I can have Ruby on Rails. But, after getting it all set up, I heard you could have it on windows as well.
Well, a Windows server is more expensive that Linux and Ruby on Rails was primarily developed for Linux, anyway, so you made the right choice. In my opinion, there really isn't any reason to go with a Windows server unless you really need some Windows-specific feature.