How to Linux disable X Windows KDE during system boot

Q. How can I configure my system to disable X Windows KDE during Linux system coming up / booting up?
A. Usually almost all Linux distribution use following runlevels for text and GUI mode:
=> Runlevel - 2/3 : Text mode
=> Runlevel - 5 : GUI mode
These modes are defined in /etc/inittab file.
Open file /etc/inittab
# vi /etc/inittab
Find out entry that read as follows:
id:5:initdefault:
Set the default runlevel to 3 (text mode)
id:3:initdefault:
Save and close the file
Reboot the system
# reboot
Now you will boot into text mode only. If you want to see GUI (KDE desktop) type the following command:
$ startx