- In the file /etc/X11/gdm/gdm.conf , change the line that reads :
- In the file /etc/inittab, change the line that reads :
ca:ctrlaltdel:/sbin/shutdown -t3 -r nowto
ca:ctrlaltdel:echo "You are not authorized to turn off the machine"
- In the directory /etc/security/console.apps/, delete the file reboot, poweroff and halt.
- Remove the file /usr/bin/poweroff
Now only the root user will be able to turn off or reboot the machine.