When ever I press alt+ctrl+del together.. there's a box that says Task manager has been disabled by your administrator. What should I do to enable it? It will be helpful if you provide a step by step answer. Thank You.

Login as an administrator. The account you tried ctrl+alt+del from does not have permission to start the task manager.
H

Login as an administrator.
H

How to login as an administrator?

Task Manager has been disabled by your administrator
It's freeware
Task Manager Fix (http://www.taskmanagerfix.com/)