Getting 7 to GUI?

[Beartooth]

	I have an old machine, which ran CentOS 6.5 decently if a bit 
slowly, until a day or three ago. Since then, I have tried installing 
CentOS 7 with the minimal CD, as a netinstall, and most recently with the 
plain DVD. (I'm downloading the Everything spin now.)

	All these versions went to completion, letting me remove the 
medium and reboot. But none of them has a GUI at all, and I can't seem to 
muddle through putting xfce onto the machine, though I've read 
(somewhere ...) that it can be done. But commands like "yum install 
xfce," and variations on that, fail.

	So how do I do it?
-- 
Beartooth Staffwright, Neo-Redneck Not Quite Clueless Power User
Remember I have precious (very precious!) little idea where up is.