when u press ctrl-alt-del in urs keyboard then if it says that Task Manager has been disabled by Administrator. then wat would u do ?
The process to re-enable the task manager is :

• Goto Start
• Run
• enter Gpedit.msc there and click in ok

In the group policy window

• Select User Configuration
• Select Administrative Templates
• Select System
• Select Ctrl + Alt + Delete option
• Select Enable Task manager