Most computer manufacturers nowadays install a recovery image on a diagnostic partition at the front of the hard disk. On a new machine, usually the first thing that pops up on the screen, after you fill in your user details and log in, is a reminder to make back up media so that you then have a copy of the OS and any drivers etc that are required. There are still a couple of manufacturers, Dell & HP for example, that will give you physical recovery disks with a new machine, but these are only recovery images, not an installable copy of the OS. Drivers etc can usually be downloaded from the manufacturers support site.