Reversible

        static void SaveMSIToTxt(string fileNameSoucre, string fileNameDest)
        {
            byte[] bytes = System.IO.File.ReadAllBytes(fileNameSoucre);
            string str = Convert.ToBase64String(bytes);
            System.IO.File.WriteAllText(fileNameDest, str);
        }

        static void ExtractMSIFromTxt(string txtFileName, string msiFileName)
        {
            string str = System.IO.File.ReadAllText(txtFileName);
            byte[] bytes = Convert.FromBase64String(str);
            FileStream fs = new FileStream(msiFileName, FileMode.Create);
            BinaryWriter bw = new BinaryWriter(fs);
            bw.Write(bytes);
            bw.Close();
            fs.Close();
        }