you can do C in visual studio even without a patch...
when you start a project just choose to create an empty solution, then add a new file, called [name].c
C isn't exactly object orientatedno.
where you have objects and properties of said objects., properties have values and you refere to each of them specifically noting the object.
what C does have going for it, (more than practically any other language) is the enforced rigidity of the code, every valiable is explicit, insize and type. (however this can cause problems with overflows if you don't do it right).
it has a very very small package form, (typically a few KB) it is very very widely used.
You can write console aplications, language parsers, web aplications, database applications, network applications, embedded device applications. (I cant think of any other languages where you can do all of those in one common language, without the need to port the languae between platforms)...
just as a side note, network aplications do require some porting, but the objects (MFC sockets / BSD sockets) used have the same syntax, just different resources.