Cancelling

Tasks use background threads from the thread pool.
To cancel a task you need to pass a special cancellation token to the task factory.

System.Threading.Cancellation.TokenSource tokenSource = new System.Threading.CancellationTokenSource(); 
System.Threading.Task.Factory.StartNew( () => System.Console.WriteLine("my new task"), tokenSource.token); 
System.Threading.Thread.Sleep(2500); 
tokenSource.Cancel();