Tuesday, August 7, 2007

Interactive task’s GUI does not appear on System Console

If a scheduled task fires at such a time when no one is logged into the system, the GUI will not visible to the user if he logs in later on (even from the console). However the process would be running on the system. It happens because:

  1. The task is launched in the security context of the 'Run As' configured user of the task.
  2. Windows looks for an active available session for that user.
  3. If Windows finds a session the task is launched in that user's Desktop.
  4. If Windows does not find the user's sessions the task is launched as a background task.

However remember the task would be launched in the console session only if more then one sessions for the same user are active on the box. Running interactive schedule tasks in TS sessions is not advisable and can give unpredictable results.


In contrast if the Task was scheduled as an 'AT' task the GUI would appear to any user who logs in to the console. This is true even if the user logs in to the console after the task was fired up. The following things should be kept in mind for AT tasks.

  1. AT tasks run in the SYSTEM security context.
  2. An AT task cannot access network resources because it is NOT running as a user.
  3. You open an AT task in Task scheduler GUI and do anything, it no longer remains an AT task.

There apparently are two type of schedule tasks available in Windows:

  1. Tasks that are scheduled / created using Task scheduler GUI.
  2. Tasks that are scheduled / created using 'AT' command.

AT tasks can be seen in the GUI of Task scheduler but you cannot create and modify them there. However Task Scheduler tasks are not visible using the AT command.

 

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Tags: Windows Server 2000, Windows Server 2003

Published Date: 20070822

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