My daughter and I have a MacBook Pro and Air that we use interchangeably although we each have our go-to machine. One is registered to me and the other to her. I'm wondering if we can get one upgrade of Mountain Lion tonuse on both machines?
Yes, if you use the same Apple ID in the Mac App Store.
You may do so per the license. http://support.apple.com/kb/HT4854
Whichever you DL first, quit the installer and copy the installer in /Applications to another disk or Mac.
This will save you the trouble of DLing again.
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