public void ProcessRequest(HttpContext context)
        {
            context.Response.ContentType = "image/x-icon";
         
            string name = context.Request["Name"].ToString();
           

          
            using (SqlConnection cn = new SqlConnection(myConnection.getStringaConnessione))
            {
                SqlCommand cmd = new SqlCommand("Select icona from myicons with (nolock) where Nome='" + Name + "'", cn);

                cn.Open();
                byte[] objData = (byte[])cmd.ExecuteScalar();
                cn.Close();

               

                using (System.IO.MemoryStream str = new System.IO.MemoryStream(objData.ToArray(), true))
                {
                    
                    str.Write(objData.ToArray(), 0, objData.ToArray().Length);
                    Byte[] bytes = str.ToArray();

  
        context.Response.AddHeader("Content-Disposition", "inline;Filename=\"" + Name + ".ico\"");
                    context.Response.AddHeader("Content-Length", objData.Length.ToString());
                    context.Response.BinaryWrite(bytes);
                   
                }
            }
        }

// richiamato poi con 
<asp:Image ID="Image1" runat="server" ImageUrl="test.ashx?name=Archsupp" BorderColor="Red" BorderWidth="1" />