User Configuration\Administrative Templates\Windows Components\Task Scheduler
Limits newly-scheduled tasks to items on the user's Start menu and prevents the user from changing the scheduled program for existing tasks.
This policy removes the Browse button from the Schedule Task wizard and from the Task tab of the Properties dialog box for a task. Also, users cannot edit the Run or the Start in boxes that determine the program and path for a task.
As a result, when users create a task, they must select a program from the list in the Scheduled Task wizard, which displays only the tasks that appear on the Start menu and its submenus. Once a task is created, users cannot change the program a task runs.
This policy appears in the Computer Configuration and User Configuration folders. If both policies are configured, the setting in Computer Configuration takes precedence over the setting in User Configuration.
This policy does not prevent users from creating a new task by pasting or dragging any program into the Scheduled Tasks folder. To prevent this action, use the Disable Drag-and-Drop policy.