Hi,
sorry for the late reply.
The current binaries in the download page are for 32bits. For 64bits, I am not sure what you need to do in VS. In Unix, is just passing a -m64 parameter to the compiler.
In order to compile fuzzylite in Windows, you need to execute the build.bat from the Visual Studio Terminal (or Console) available amongst the applications in the Visual Studio group when you installed Visual Studio.
Let me know if this helped.
Cheers,
Juan