win7上共享文件夹问题

 private void button1_Click(object sender, RoutedEventArgs e)
        {
            ShareDirectory("D:\\ssss", "ssss", "ssss");//设为共享
        }
        public static void ShareDirectory(string path, string ShareName, string Description)
        {
            ManagementClass _class = new ManagementClass(new ManagementPath("Win32_Share"));
            object[] obj = { path, ShareName, 0, null, Description };
            _class.InvokeMethod("Create", obj);
        }

在xp上运行可以共享文件夹，在win7上不行