ENABLE OR DISABLE A SERVICE FROM STARTUP IN UBUNTU

DISABLE A SERVICE FROM AUTOSTART IN UBUNTU
update-rc.d apache2 disable

ENABLE A SERVICE FROM AUTOSTART IN UBUNTU
update-rc.d apache2 enable

OR 

PERMANENTLY REMOVE FROM STARTUP
update-rc.d -f apache2 remove

ADD STARTUP SCRIPT AGAIN AFTER REMOVING
update-rc.d apache2 defaults


To add in stratup in RedHat/Fedora/Centos
chkconfig --add httpd