_WIN32_WINNT 定义
Windows XP _WIN32_WINNT>=0x0501
Windows 2000 _WIN32_WINNT>=0x0500
Windows NT 4.0 _WIN32_WINNT>=0x0400
Windows Me _WIN32_WINDOWS=0x0490
Windows 98 _WIN32_WINDOWS>=0x0410
Internet Explorer 6.0 _WIN32_IE>=0x0600
Internet Explorer 5.01, 5.5 _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
Windows 2000 _WIN32_WINNT>=0x0500
Windows NT 4.0 _WIN32_WINNT>=0x0400
Windows Me _WIN32_WINDOWS=0x0490
Windows 98 _WIN32_WINDOWS>=0x0410
Internet Explorer 6.0 _WIN32_IE>=0x0600
Internet Explorer 5.01, 5.5 _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