How to make a Unique folder name?

            HttpWebRequest request = (HttpWebRequest)WebRequest.Create("http://www.google.co.in/");
            HttpWebResponse response = (HttpWebResponse)request.GetResponse();
            Stream receiveStream = response.GetResponseStream();
            StreamReader readStream = new StreamReader(receiveStream, Encoding.UTF8);
            String spath1 = String.Format("G:\\Content\\{0}", DateTime.Now.ToString("ddMMyyhhmmss"));
            String spath2 = String.Format("{0}.text", DateTime.Now.ToString("ddd.dd-MMM-yyyy.hhmmsstt"));
            if (File.Exists(spath1) == false)
            {
                Directory.CreateDirectory(spath1);
            }
            StreamWriter sw = new StreamWriter(Path.Combine(spath1, spath2));
            String line;
            while ((line = readStream.ReadLine()) != null)
            {
                sw.WriteLine(line);
            }
            sw.Close();