Use UnicodeEncoding

   
 

using System;
using System.Text;

class StringEncodingApp {
    static void Main(string[] args) {
        ASCIIEncoding ae = new ASCIIEncoding();
        Console.WriteLine(ae.GetString(new byte[]{1,2,3}));
        UnicodeEncoding bu = new UnicodeEncoding(true, false);
        Console.WriteLine(bu.GetString(new byte[]{1,2,3}));
    }
}