Disable the Control-Alt-Delete keyboard shutdown

To do this comment out the line (with a "#") listed below in your "/etc/inittab" file .
To do this, edit the inittab file (vi /etc/inittab) and change the line:
ca::ctrlaltdel:/sbin /shutdown -t3 -r now
To read:
#ca::ctrlaltdel:/sbi n/shutdown -t3 -r now