Now the solution is for turn on the task manager by following these easy steps:-
Go to start and open run
Type ‘gpedit.msc’ and press run or enter
Click on ‘Administrator template’
Now click on ‘system’
Open the ‘Ctrl+alt+del option’
Now double click on Remove task manager or open it and disable it
Now your task manager is turn on.
NOTE: I used this on my system And I successfully turn on task manager, but I give no guarantee to you that this trick 100% works. So use this at your own risk.