Switch on your computer, load the Fedora 18 live CD into the CD or DVD drive, and restart the computer with the disc still in the drive. Ideally, you should soon see the Fedora boot screen and a ten-second countdown:

Either press Enter to select the Start Fedora 18 option, or wait for the countdown to expire.

If you do not see this screen, you might need to select an option manually to make your computer boot from the CD. Power your computer on, and watch the initial BIOS screen for a prompt that indicates which key to use for either:

The boot menu option is preferable. If you cannot see such a prompt, consult your manufacturer's documentation for your computer system, motherboard, or mainboard for the correct keystroke. On many systems, the required key will be F12, F2, F1, Esc, or Delete.