CTRL ALT DELETE - task manager not working. HELP PLEASE!

Hello all, I hope somebody can help me with this problem. Whenever I press CTRL, ALT, DELETE, to get my task manager to come up, a message pops up saying "Task Manager has been disabled by your administrator." Well I don't know what to do because I am the computer administrator and I did not touch anything or do anything to disable this. My question is - plain and simple - how do I fix this?:smileysad: Thanks so much in advance!