Sorting data from a TSV using C#

Hi, I want to sort the data accordinf to the 3rd column which I can but I need to leave the entire heading row intact which means I need to skip a row, dont know how, Also I need distinct data for the 3rd row which means (bim is diff than BIm). I can only get 4 rows to display, how do i get to display the rest. Here is my code.

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.IO;
namespace ConsoleApplication4
{
    class Program
    {
        static void Main(string[] args)
        {
            var records = (from l in File.ReadAllLines(@"d:\instance_test.txt")
                           let pieces = l.Split('\t')
                           select new { Col1 = pieces[0], Col2 = pieces[1], Col3 = pieces[2], Col4 = pieces[3] })
                .GroupBy(c => (c.Col1 + c.Col2 + c.Col3+c.Col4))
                .Skip(1)
                .Select(gr => gr.First())
                .Distinct()
                .OrderBy(c => c.Col3);
            for (int i = 0; i < 99; i++)
            {
            } foreach (var r in records)
            { Console.WriteLine("{0}, {1}, {2},{3}", r.Col1, r.Col2, r.Col3, r.Col4); }
            Console.WriteLine();
            Console.WriteLine("Done");
            Console.ReadLine();
        }
    }
}