Currently Being ModeratedJul 24, 2012 11:00 PM (in response to Mac OS XP)
sign into the app store on the mac you want to install ML (the other one in the household) on with the Apple ID used to purchase ML. Hold the option key while clicking on purchases tab and then click the dark grey install button.
Currently Being ModeratedJul 24, 2012 11:04 PM (in response to shldr2thewheel)
Okay, but I'm going to call that Plan B since we have relatively slow internet and downloading once takes half a day. I know that it is possible to make a DVD from the installation file before actually installing the upgrade on my MacBook Pro. Would I be able to just insert such a DVD to update the iMac, or would that also require entering an Apple ID, or would it require a clean install (if so I would just download twice)?
Currently Being ModeratedJul 24, 2012 11:08 PM (in response to Mac OS XP)
Hope this helps:
Currently Being ModeratedJul 24, 2012 11:10 PM (in response to Mac OS XP)
Someone else in my household has an aluminium iMac running Snow Leopard, so I was wondering how to upgrade that computer as well, considering that it has a different user with a separate Apple ID.
Make sure the iMac meets Mountain Lion's requirements here > Apple - Upgrade your Mac to OS X Mountain Lion.
Currently Being ModeratedJul 24, 2012 11:14 PM (in response to Carolyn Samit)
It does, it's from like 2008 or 2009 I think. So all I'm still wondering is if a DVD made from the first download of the installation file can perform a regular upgrade (like the old Snow Leopard DVDs did). I say DVD and not USB because I don't really want to dedicate my only thumb drive that's big enough to this and I already have rewritable DVDs at my disposal.
Currently Being ModeratedJul 25, 2012 6:27 AM (in response to Mac OS XP)
Yes you should be able to upgrade all the Macs you control in your home (including children at college) from one downloaded copy of Mountain Lion. Just make sure you make a copy of the installer before attempting to install it on the first system, as the install process deletes the installer when finished, so you want that copy before the install starts or you need to download it again.
You can make an installer DVD, or you can copy the installer to the other Mac(s).
Also large capacity USB thumb drives are dirt cheap theses days (assuming you do some on-line shopping <http://dealmac.com>). DVD is fine as well.
Currently Being ModeratedJul 27, 2012 6:03 PM (in response to BobHarris)
Now I read this... Unfortunately I already installed Mountain Lion on my iMac prior to reading this good advice. Now I guess the App Store will know that I already have paid, when I go to download it on my MacBook Air. I have to go purchase a USB to Ethernet cable because it woud take a week to download the OS to my MBA via WiFi. Any better way to do this?
Currently Being ModeratedJul 27, 2012 6:08 PM (in response to WiseJD)
WiFi should be almost as fast as your ethernet connection, I suggest you see how it goes. Otherwise, know that you are able to go back to the App Store on your iMac, hit the Purchases tab on top, and you can download Mountian Lion again. At that point you can transfer the app to a thumb drive (or make a bootable USB drive if you want) to put it on the MBA.
Currently Being ModeratedJul 29, 2012 6:45 AM (in response to Mac OS XP)
You were correct, it took only about 25% more with WiFi.