File Stream C#

using System;
using System.IO;
public class DirectoryRoot
{
    public static void Main()
    {
        string dir = @"C:\test";
        try
        {
            //Set the current directory.
            Directory.SetCurrentDirectory(dir);
        }
        catch (DirectoryNotFoundException e)
        {
            Console.WriteLine("The specified directory does not exist. {0}", e);
        }
        Console.WriteLine("Root directory: {0}", Directory.GetDirectoryRoot(dir));
        Console.WriteLine("Current directory: {0}", Directory.GetCurrentDirectory());
    }
}