Minimum Windows runtime version depends on libc shipped with MSVC compiler, for Visual Studio 2008 it's Windows 2000 SP4; for VS2010 it's Windows XP SP3; for VS2013/VS2015 it's Windows 7 IIRC. There's also /Zl compiler option to omit libc entirely (e.g. for small programs using only Win32 API).
MSVCRT.DLL used to be default runtime library for code produced by Microsoft Visual Studio 6 compiler. This DLL is still shipped with Windows, albeit its sprintf() doesn't support %ll format specification, its time() function assumes that time_t is 32-bit, and in general it feels very 1998y. It required some redist on Win95 and NT4 IIRC.
MSVCRT.DLL used to be default runtime library for code produced by Microsoft Visual Studio 6 compiler. This DLL is still shipped with Windows, albeit its sprintf() doesn't support %ll format specification, its time() function assumes that time_t is 32-bit, and in general it feels very 1998y. It required some redist on Win95 and NT4 IIRC.