How can i use a Session in case of a file download situation in c#, not asp?

I'm trying to download set of files from web and im writing a C# console app. And im using web client to do this. The problem is it wont able to download the file unless i open the file download link in the browser. I don't know the reason why this happens. I was thinking this has something to do with sessions. Any help would be appreciated.

This is my code

private bool DownloadFile(string pdfId, string filetype)
{
        try
        {
            using (WebClient webClient = new WebClient())
            {
                webClient.DownloadFile("http://ift.tt/1owUhlA", "E:\\New\\File.pdf");
            }                           
            return true;
        }
        catch (Exception ex)
        {
            Execption = ex.Message;
            return false;
        }         
}

The error im getting is

"The remote server returned an error:(404) not found"