Use this instead:
kernel.Bind(scanner => scanner
.FromThisAssembly()
.SelectAllInterfaces()
.EndingWith("Factory")
.BindToFactory());
kernel.Bind(scanner => scanner
.FromThisAssembly()
.SelectAllClasses()
.EndingWith("Task"));
var f = kernel.Get<ITaskFactory>();
var task1 = f.CreateTask<AlertTask>();
var task2 = f.CreateTask<PopupTask>();
public class AlertTask {}
public class PopupTask { }
public interface ITaskFactory
{
T CreateTask<T>();
}