Most people already know that MacBook Air units are packaged with a Leopard OS X 10.5 installation CD. Like systems before it, Apple has locked these installation disks to the unit. This means that it will only work on a MacBook Air.

In addition to locking the installation disks to the system, users are advised to refrain from using other Leopard OS X 10.5 installation discs on the MacBook Air. Here's what's been posted on Apple's support group webpage:

The Mac OS X 10.5 installation media that shipped with your MacBook Air is designed for use on this computer only and not intended for any other computer.

The installer prevents this software from being installed on other Macintosh computers. Furthermore, other Mac OS X 10.5 installation media should not be used when restoring the system software on your MacBook Air.

This shouldn't really come as a surprise, considering the operating system running on the MacBook Air has support for multi-touch gestures and Remote Disc, something stock Leopard OS X 10.5 doesn't have. Still, this is a pretty good reminder from Apple to avoid any unwanted problems when using the MacBook Air.