So, you would need to check to see if you have software on your Mac that maybe older than, say, 2006 or older. The use of Rosetta ended with OS X Snow Leopard as the Rosetta application was licensed to Apple, from a software company called Transitive, which got bought out, I believe, by IBM and Appe could no longer secure their rights to continue to use Rosetta in later versions of OS X. OS X Snow Leopard had a magical and invisible PowerPC emulation application, called Rosetta, that worked seamlessly in the background that still allowed older PowerPC coded software to still operate in a Intel CPU Mac. If you run any older Mac software from the earlier PowerPC Macs, then none of this software will work with the newer OS X versions (10.7 and onward). Newer versions of the Mac OS need 8 GBs of RAM or more. OS X Mountain Lion, Lion, or Snow Leopard v10.6.8 already installedĢ GB or more of memory (I strongly advise, at least, 4 GBs of RAM or more) Your 2007 iMac can take a total of 6 GBs of RAM. MacBook Pro (15-inch or 17-inch, Mid/Late 2007 or later) MacBook Pro (13-inch, Mid-2009 or later),

MacBook (13-inch Aluminum, Late 2008), (13-inch, Early 2009 or later) To download and install either the pay OS X 10.8.5 Mountain Lion or the free macOS Sierra OR OS X 10.11.5 El Capitán you need one of these Macs:

Then, determine if your Mac meets ALL minimum system install requirements.

This step is really needed in case something goes wrong with the install of the new OS or you simply do not like the new OS, you have a very easy way/procedure to return your Mac to its former working state. Then, use either OS X Time Machine app to backup your entire system to the external drive OR purchase, install and use a data cloning app, like CarbonCop圜loner or SuperDuper, to make an exact and bootable copy (clone) of your entire Mac's internal hard drive. Late 2006 iMac models could only be upgraded to OS X 10.7.5 Lion.īefore embarking on a major OS upgrade, it would be wise, advisable and very prudent if you have a good, working backup of your current system to an external connected and Mac formatted Flash drive OR externally connected USB, Thunderbolt or FireWire 800, Mac formatted hard drive.

If your iMac is stuck at OS X 10.7.5 Lion, that iMac may not be a 2007 iMac, but a 2006 iMac that you purchased in 2007.

Upgrade mac 10.7.5