Clion on Windows 8.1: cmake hangs?

Hi,
During the day I'm primarily working in Visual Studio, hence ReSharper C++ ;-) Thought I would give CLion a try.

The underlying tools (gcc etc) are not that familiar to me... But, anyway I got the simple 'hello world' project compiled and running on Windows 7 64 bit with cygwin 64 bit.Then I tried exactly the same thing under Windows 8.1 64 and had issues. Basically, cmake seems to hang. E.g. when opening the project, and similarly in the toolchain window. Seem images open_project.png and toolchain.png. Newbie mistake I guess, but what? Anyone any ideas?

Thanks,
Dave