I'm trying to create a second drive with a legacy OS, and I am having problems that seem ridiculous. Am I missing something in this process? Computer : MAC MINI 2012 i7 Int. Drives: 1TB SSD w/10.13 + 256GB SSD w/nothing (hope to install OSX Mtn. Lion) Thumbdrive: 16GB Toshiba with OSX Mtn. Lion disk image installed on it OK. What I want to do is get the 256SSD reformatted with MOUNTAIN LION. Problem: Restarting with OPTION held down always gives me errors and crashes the computer before the Thumbdrive Man. Lion disk can start up. • I downloaded Mountain Lion's installer • Found contents, went into shared folder • Used disk image to create thumb drive disk • Thumbdrive disk has Install OS X Mountain Lion/Library/Packages/System Is Mountain Lion too far back? Is there something missing in this process? I really need help to figure this out. I'm trying Mavericks next, to see if Men. Lion is too old for this mini. Thanks for any help.