It can boot off a USB formatted properly with an installer. /rebates/&.com252fmac-computers252f8h94u-upgrade-mac-operating-system-lion-maverick.
#How to upgrade imac operating system from lion install#
You may find simply find that a fresh install would do it some good. Lion is the newest officially (provided the iMac has 2 GB or more RAM), but Mountain Lion can be installed unofficially using MLPostFactor. Refresh Yourselfīelieve it or not, even on a Mac you may find you want to wipe your hard drive and do a fresh install of OS X as your machine ages. If not, I guess it’s back to the Snow Leopard disc for you and then another run at Lion. If your Internet connection fails or the power goes out in the middle of your installation, it’s best to have the new OS on a DVD or USB stick so that you can reboot and try to install again. Perhaps your experience is the same, but I bet you know someone who has had an OS installation nightmare.įor that reason alone, the idea of upgrading to OS X without a physical disc makes me queasy. Get even more transparency around your privacy. Discover new features for Maps and Messages. Experience Mac to the fullest with a refined new design. Now, I admit, I have upgraded many computers running versions of Windows, OS X, and Linux, and I have never run into a problem. macOS Big Sur elevates the most advanced desktop operating system in the world to a new level of power and beauty.
Just like Windows users who wanted to wipe their hard drives before upgrading to Vista from XP, it sounds like OS X Lion users will end up tied to a double OS installation.