Task Scheduler 1.0 Task Scheduler 1.0 is included with
Windows NT 4.0 (with
Internet Explorer 4.0 or later),
Windows 2000, and
Windows Server 2003. It runs as a
Windows Service, and the task definitions and schedules are stored in
binary .job files. Tasks are manipulated directly by manipulating the .job files. Each task corresponds to single action. On
Windows 95 (with
Internet Explorer 4.0 or later),
Windows 98 and
Windows Me, the Task Scheduler runs as an ordinary program, mstask.exe. It also displays a status icon in the notification area on Windows 95 and Windows 98 and runs as a hidden service on Windows Me, but can be made to show a tray icon. Computer programs and
scripts can access the service through six
COM interfaces. Microsoft provides a scheduling agent DLL, a sample
VBScript and a configuration file to automate Task Scheduler. In addition to the graphical user interface for Task Scheduler in
Control Panel, Windows provides two command-line tools for managing scheduled task:
at.exe (deprecated) and schtasks.exe. However, at.exe cannot access tasks created or modified by Control Panel or schtasks.exe. Also, tasks created with at.exe are not interactive by default; interactivity needs to be explicitly requested. The binary ".job" files which the AT command produces are stored in the %WINDIR%\Tasks directory.
Task Scheduler 2.0 Task Scheduler 2.0 was introduced with
Windows Vista and included in
Windows Server 2008 as well. logoff, or only during or for a specified time.
XPath expressions can be used to filter events from the
Windows Event Log. Tasks can also be delayed for a specified time after the triggering event has occurred, or repeat until some other event occurs. Actions that need to be done if a task fails can also be configured. The actions that can be taken in response to triggers, both event-based as well as time-based, not only include launching applications but also take a number of custom actions. Task Scheduler includes a number of actions built-in, spanning a number of applications; including send an e-mail, show a message box, or fire a
COM handler when it is triggered. Custom actions can also be specified using the Task Scheduler API. Task Scheduler keeps a history log of all execution details of all the tasks. Windows Vista uses Task Scheduler 2.0 to run various system-level tasks; consequently, the Task Scheduler service can no longer be disabled (except with a simple registry tweak). Task Scheduler 2.0 exposes an
API to allow computer programs and scripts create tasks. It consists of 42
COM interfaces. The Windows API does not, however, include a
managed wrapper for Task Scheduler though an open source implementation exists. The job files for Task Scheduler 2.0 are
XML-based, and are human-readable, conforming to the
Task Scheduler Schema.
Other features • New security features, including using
Credential Manager to passwords for tasks on
workgroup computers and using
Active Directory for task credentials on
domain-joined computers so that they cannot be retrieved easily. Also, scheduled tasks are executed in their own session, instead of the same session as system services or the current user. • Ability to wake up a machine remotely or using
BIOS timer from sleep or hibernation to execute a scheduled task or run a previously scheduled task after a machine gets turned on. • Ability to attach
tasks to
events directly from the
Event Viewer. ==Tasks==