yum install x windows

if you have minimal install on your centos server, we can add x windows by using this from ssh

yum groupinstall 'X Window System' 'GNOME Desktop Environment' 'Sound and Video'

i'm using reference from this website: http://lists.centos.org/pipermail/centos/2006-April/020567.html

Transaction Summary 
============================================================================= 
Install    196 Package(s) Update       2 Package(s) 
Remove       0 Package(s) 
Total download size: 253 M 
Is this ok [y/N]: y 
Downloading Packages: warning: rpmts_HdrFromFdno: V3 DSA signature: NOKEY, key ID 6b8d79e6