I'm still using MSVC6 for Windows development. Makes tiny, portable executables (no pun intended) that link to the standard MSVCRT.DLL system runtime, not their bloated and awfully overdesigned successors.
The C library is the C library. There should never be a reason for there to be multiple versions in any normal application. If I remember correctly even MS' own executables are linked to MSVCRT.DLL