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?
No. You cannot reuse the preinstalled ML. You will need to buy another copy to share amongst your other Macs. The preinstalled OSX is for that Mac only.
In other words, how do i get OS X 10.8 on my old MBP without having to shell out another $19.99?
You can't. The license that comes with the preinstalled OS is for that Mac only. If you want to run that OS on other Macs, you need to buy a copy from the online store. The license for that copy is good for all the Macs you own or control.
Since your machien shipped with Mountain Lion, you SHOULD find it under the Purchases tab or simply be able to download it for free. If you're unable to do so, contact the Mac App Store support folks - http://www.apple.com/support/mac/app-store/.
After you do downloaded it, it will start an installation. Quit the installations and you'll find a file in your Applications folder named "Install OS Mountain Lion.app". Get an 8GB+ USB flash drive, or a blank dual-layer DVD and use Lion DiskMaker to make a bootable installation disk. Then you can update your other computers without having to download it again.
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.
You're right... sorry. I remember that when I received my MacBook Pro, which shipped with Lion, that I had to PAY for Lion to download it and make a backup installer USB disk.
Note that without buying a new copy you can install Mountain Lion on a backup drive (by booting into the Restore HD & choosing that drive for the destination), but it will only work with that Mac. (This does not violate the licensing terms because of the "at any one time" qualifier.)
Also note that this does not apply to the preinstalled bundled iLife apps. As long as your other Macs can run the latest version (for all except GarageBand OS 10.7 is required) you can install them on your other Macs from the MAS. Just sign in with your Apple ID from your other Mac(s) & they will show up in the Purchases tab.