I would like to compile a file c, I get the following error:
cannot compile c file with /ZW option
When changing project properties in Visual Studio, remember often need to set Configuration All Configurations and Platform to All Platforms. This can be particularly confusing when you are changing the properties of the non-active configuration/platform and your changes don't seem to have any effect.
Note that you can use C language files in a UWP project, but you can't consume Windows Runtime APis using C. C++ is required for both C++/CX language extensions as well as the new C++ WinRT language projections.