asp.net save pdf file to local driv

I assume by local drive you mean browser side (as opposed to server side)?

If so you have no control over that at all. You can send the attachment back to the user such that it opens automatically or they are prompted to save it. But where they save it is up to them.

To automatically open an attachment:

Response.AppendHeader("Content-Disposition", "inline; filename=doc1.pdf");

Select all Open in new window

To prompt to save:

Response.AppendHeader("Content-Disposition", "attachment; filename=doc1.pdf");

Select all Open in new window

how about if i would like to set the location of the local drive?

As I said "If so you have no control over that at all" :)

found this,

protected void Page_Load(object sender, EventArgs e)
{  

    FileStream fs = File.OpenRead(Server.MapPath("~/imgName.jpg"));
    byte[] buffer = new byte[(int)fs.Length];
    fs.Read(buffer, 0, (int)fs.Length);
    fs.Close();
    SetResponse("imgName");
    HttpContext.Current.Response.BinaryWrite(buffer);
    HttpContext.Current.Response.Flush();
    HttpContext.Current.Response.Close();
}

private static void SetResponse(string fileName)
{
    string attachment = "attachment; filename=" + fileName + ".jpg";
    HttpContext.Current.Response.Clear();
    HttpContext.Current.Response.ClearHeaders();
    HttpContext.Current.Response.ClearContent();
    HttpContext.Current.Response.AddHeader("content-disposition", attachment);
    HttpContext.Current.Response.ContentType = "image/jpeg";
    HttpContext.Current.Response.AddHeader("Pragma", "public");
}