Suppose you've VC6.0 installedFile-->New---> Choose Either of
1, Projects Tag--> Win32 Console Application
2, Files Tag--> C++ Source File
Then you can do basic C/C++ programming.
If you want to see the output, just press F5(Debug mode)
or Build-->Rebuild All to make the executable.
C++ is back-compatible with C
(C++ is a super-set of C)
so do not worry whether the file extension is .c or .cpp
but for O/S module, you'd better do C programming in UNIX since there are some functions(system calls terminologically) which are specific to the O/S, and cannot be recognised by VC..