ref : http://hi.baidu.com/hust_junejun/blog/item/d86557a3cd49f8a6caefd0f9.html
The following table describes the preferred macros in use by the Windows header files.
Minimum system required Macros to define
Windows Server 2008 NTDDI_VERSION >= NTDDI_LONGHORN
Windows Vista NTDDI_VERSION >= NTDDI_VISTA
Windows Server 2003 SP1 NTDDI_VERSION >= NTDDI_WS03SP1
Windows Server 2003 NTDDI_VERSION >= NTDDI_WS03
Windows XP SP2 NTDDI_VERSION >= NTDDI_WINXPSP2
Windows XP SP1 NTDDI_VERSION >= NTDDI_WINXPSP1
Windows XP NTDDI_VERSION >= NTDDI_WINXP
Windows 2000 SP4 NTDDI_VERSION >= NTDDI_WIN2KSP4
Windows 2000 SP3 NTDDI_VERSION >= NTDDI_WIN2KSP3
Windows 2000 SP2 NTDDI_VERSION >= NTDDI_WIN2KSP2
Windows 2000 SP1 NTDDI_VERSION >= NTDDI_WIN2KSP1
Windows 2000 NTDDI_VERSION >= NTDDI_WIN2K
The following table describes the legacy macros in use by the Windows header files.
Minimum system required Macros to define
Windows Server 2008 _WIN32_WINNT>=0x0600
WINVER>=0x0600
Windows Vista _WIN32_WINNT>=0x0600
WINVER>=0x0600
Windows Server 2003 _WIN32_WINNT>=0x0502
WINVER>=0x0502
Windows XP _WIN32_WINNT>=0x0501
WINVER>=0x0501
Windows 2000 _WIN32_WINNT>=0x0500
WINVER>=0x0500
Windows NT 4.0 _WIN32_WINNT>=0x0400
WINVER>=0x0400
Windows Me _WIN32_WINDOWS=0x0500
WINVER>=0x0500
Windows 98 _WIN32_WINDOWS>=0x0410
WINVER>=0x0410
Windows 95 _WIN32_WINDOWS>=0x0400
WINVER>=0x0400
Internet Explorer 7.0 _WIN32_IE>=0x0700
Internet Explorer 6.0 SP2 _WIN32_IE>=0x0603
Internet Explorer 6.0 SP1 _WIN32_IE>=0x0601
Internet Explorer 6.0 _WIN32_IE>=0x0600
Internet Explorer 5.5 _WIN32_IE>=0x0550
Internet Explorer 5.01 _WIN32_IE>=0x0501
Internet Explorer 5.0, 5.0a, 5.0b _WIN32_IE>=0x0500
Internet Explorer 4.01 _WIN32_IE>=0x0401
Internet Explorer 4.0 _WIN32_IE>=0x0400
Internet Explorer 3.0, 3.01, 3.02 _WIN32_IE>=0x0300