Download, Upload and sownload .zip file

you can write this code in page load event so that it will make list of all the .zip files

    DirectoryInfo directory = new DirectoryInfo(Server.MapPath("~/Files"));

       int counter = 0;

        foreach (FileInfo file in directory.GetFiles())

        {

            HyperLink link = new HyperLink();

            link.ID = "Link" + counter++;

            link.Text = file.Name;

            link.NavigateUrl = "Default2.aspx?name="+file.Name;

            Page.Controls.Add(link);

            Page.Controls.Add(new LiteralControl("
"));

        }

and new page named Default2.aspx and in that page load event write below code

protected void Page_Load(object sender, EventArgs e)

    {

        string fileName = Request.QueryString["name"].ToString();

        Response.ContentType = "application/octet-stream";

        Response.AddHeader("Content-Disposition", "attachment;filename=" + fileName);

        Response.TransmitFile(Server.MapPath("~/Files/" + fileName));

        Response.End();

    }

may be it helps.