To install desktop on Centos releases, and make it autostart after boot,
1) Install epel release
yum install epel-release
2) Group install X windows and Desktop
yum groupinstall "X Window System"
yum group install "Desktop"
3) Make it auto start after boot. Edit /etc/inittab file and set the default
runlevel to 5 such as in the file "id:5:initdefault:"