Cannot create a new project

I've downloaded the community edition (I'm new to Java but a professional C# developer), I'm running on Windows 8.1

I start the IDE, select Create New Proejct and then get a New Project dialog,

That dialog looks like this:



The dropdown list "Project SDK" is empty yet it seems I must select something in there to continue, also checking "Groovy" causes an error:



None of this makes any sense, it seems there are prerequistites that I'm unaware of, is that true?

Thanks.