public void HashFile(String FPath)
    {
        using (var md5 = MD5.Create())
        {
            using (var stream = File.OpenRead(FPath))
            {
                String ComputedHash = BitConverter.ToString(md5.ComputeHash(stream)).Replace("-", String.Empty).ToLower();

                WriteToFile(FPath + "  " + ComputedHash);
            }
        }
    }