Is ur Task Manager has stopped responding Here is The Solution

Enable or Disable Task Manager

Just go to:

• Click Start
• Click Run
• Enter gpedit.msc in the Open box and click OK
• In the Group Policy settings window
o Select User Configuration
o Select Administrative Templates
o Select System
o Select Ctrl+Alt+Delete options
o Select Remove Task Manager
o Double-click the Remove Task Manager option

and close it now u will b able to switch it on or off.Bye And Thanks