I just bought a new MBP with OS X 10.8 preinstalled. I also understand that a single OS X license is valid for up to 5 personal Macs. Even though i registered the new MBP with my Apple ID when i first turned it on, the OS X doesn't seem to be associated with my Apple ID. Therefore, when i look at my Purchases in the App Store, Mountain Lion is not there, as this Apple Support page suggests.
How can i use my Mountain Lion OS X license (that i purchased preinstalled on my new MBP) on my old MBP? In other words, how do i get OS X 10.8 on my old MBP without having to shell out another $19.99?
Is there a way to assign my Apple ID to my OS X 10.8 that's already purchased? Is there a way to copy the OS X 10.8 to a bootable flashdrive or DVD-R that can be used on a seperate MBP?
Since your machien shipped with Mountain Lion, you SHOULD find it under the Purchases tab or simply be able to download it for free.
You can find it in the purchases tab only if you have purdhased it from the Mac App Store. Preinstalled OS's do not qualify.
From the OS X 10.8.2 license (emphasis added):
A. Preinstalled and Single-Copy Apple Software License. Subject to the terms and conditions of this License, unless you obtained the Apple Software from the Mac App Store or under a volume license, maintenance or other written agreement from Apple, you are granted a limited, non- exclusive license to install, use and run one (1) copy of the Apple Software on a single Apple- branded computer at any one time. For example, these single-copy license terms apply to you if you obtained the Apple Software preinstalled on Apple-branded hardware.