Disabled Ctrl+Alt+Del and Preventing users from Task manager with GP-Editor

gpedit
  1. Click the Start button and select Run. Enter “gpedit.msc”.
  2. Go to User Configuration >> Administrative Templates >> System >> Ctrl+Alt+Del Options look for a setting named Remove Task Manager and double-click on it.
  3. Select “Enabled” then click OK.
  4. Done, you may need to restart the computer to make it works.