If you used the At command in Windows NT, you're familiar with the concept of scheduling programs. The At command is still available in Windows 2000, and you can use it to schedule tasks. However, several differences between the At command and Win2K's Task Scheduler make the new tool easier to use and configure. The most obvious advantage is Task Scheduler's graphical interface, but equally important are its flexibility, which lets you configure tasks to run in a variety of different security contexts, and its auditing capabilities. Task Scheduler is a COM-based object, which means you have a common API set.
The At command and Task Scheduler work together. When you use the At command to schedule a task, that task appears in the Scheduled Tasks window. To reconfigure the task, you can use At command switches or Task Scheduler features. However, after you use Task Scheduler to change a task's configuration, the At modifiers no longer work on that task—you've committed your modification efforts to Task Scheduler.