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