CentOS is a robust Linux distribution used primarily in Web server environments. CentOS provides a stable server platform and is available as a free, open-source operating system for use by hosting providers and end users alike. While CentOS is a powerful Web server OS with many Internet related features, it lacks a graphical user interface with basic installations. Consequently, if you want enable a GUI from the CentOS command line, you'll need to first download and install a compatible graphical desktop environment, such as Gnome or KDE.
Log in to the CentOS operating system.
Type the command "su -" to switch to a root session.
Type the command:
yum groupinstall "X Windows System" "GNOME Desktop Environment" or yum groupinstall "X Windows System" "KDE Desktop Environment"
to install your preferred desktop environment.
Type the command "startx" to start the X windows system and your preferred desktop environment.
If you already have a graphical desktop environment installed, you can just type "startx" as the root user.