CreateProcess不能在所有应用程序上都起作用

CreateProcess(FullPathOfExternalApp.c_str(), NULL, NULL, NULL, false, CREATE_DEFAULT_ERROR_MODE, 0, 0, &siStartupInfo, &piProcessInfo)

std::string getSystemErrorMsg()
{
    LPVOID lpMsgBuf;
    ::FormatMessage( FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM, NULL, GetLastError(), MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL );

    std::string err = reinterpret_cast<const char *>( lpMsgBuf );

    ::LocalFree( lpMsgBuf );

    return err;
}