Insert the DVD to DVD drive, select DVD drive as booting device.  When see the boot prompt, and press ENTER key.  To access Internet, the Live DVD must run in network which IP address is given by the DHCP service, likes Internet boardband router. As DVD is slow media, the system startup speed highly depends on your DVD drive reading speed and media type you use.  It may take a bit of time for booting.

After Linux boot up, login the system to user "root", no password is required. Then start the GNOME desktop by typing "startx" as below figure shown.

With a short moment, the full GNOME Desktop should be correctly shown on the screen as shown on below figure.