在使用一些新版本的API，或者控件的新特性（比如新版的ComCtl32.dll）的时候,你可能会得到“error C2065: undeclared identifier.“这个错误。
原因是这些功能是依赖于你的操作系统的版本的。而你的头文件中的定义并不是最新的。
（对于MFC,就是stdafx.h）下面详细列举了每个Windows版本对应的NTDDI_VERSION，_WIN32_WINNT，WINVER，_WIN32_IE这些宏。
NTDDI_VERSION:
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
_WIN32_WINNT|WINVER:
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
_WIN32_IE:
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