CentOS7
start in non-graphical mode
systemctl set-default multi-user.target
start in GUI
systemctl set-default graphical.target
At boot screen (GRUB)
http://superuser.com/questions/426488/how-to-boot-centos-in-cli
Edit kernel line pressing e
Search for the kernel line and append a 3 to the end (runlevel 3 means text mode)
Change from text mode to GUI using runlevels
/sbin/telinit 5