using System;

using System.Text;

using System.Security.Cryptography;

public class Program

{

    public static void Main()

    {

        var hash1 = MD5.Create().ComputeHash(Encoding.Default.GetBytes("Hello World!"));

        var hash2 = MD5.Create().ComputeHash(Array.Empty<byte>()); // 00000000      

​

        var guid1 = new Guid(hash1).ToString("N");

        var guid2 = new Guid(hash2).ToString("N"); // not 0000000 !

        Console.WriteLine("guid1 " + guid1);        

        Console.WriteLine("guid2 " + guid2);

    }

}