下面是彻底解决方法：
在工程的stdafx.h中添加（如有类似语句，需注释掉）
#ifndef WINVER // Allow use of features specific to Windows 95 and Windows NT 4 or later.
#define WINVER 0x0501 // Change this to the appropriate value to target Windows 98 and Windows 2000 or later.
#endif
#ifndef _WIN32_WINNT // Allow use of features specific to Windows NT 4 or later.
#define _WIN32_WINNT 0x0501 // Change this to the appropriate value to target Windows 98 and Windows 2000 or later.
#endif
#ifndef _WIN32_WINDOWS // Allow use of features specific to Windows 98 or later.
#define _WIN32_WINDOWS 0x0501 // Change this to the appropriate value to target Windows Me or later.
#endif
#ifndef _WIN32_IE // Allow use of features specific to IE 4.0 or later.
#define _WIN32_IE 0x0601 // Change this to the appropriate value to target IE 5.0 or later.
#endif