I have a Mac mini 2007 (Core 2 Duo - 64 bit processor with a 32 bit EFI) that still runs OS X Lion, the last version provided by Apple for this machine. I have looked in the past at threads here on running newer versions of OS X on the Macs unsupported by Apple. For various reasons, I never got a lot of confidence in installing and running a newer version without issues. I would like to know: 1. Which newer OS X version should I try? My requirements are for the system to run well without crashing and without fundamental issues like no video or no audio or no USB, etc. I'm not looking for fancy graphics effects, translucency, FaceTime, etc. 2. I would prefer a version that would get security updates at least for another year. But this is not a strict requirement since I've already been without security updates for long enough. 3. Can you point me to a comprehensive guide that you have followed for a Mac mini 2007 Core 2 Duo and gotten it working? Any caveats or additional things to take care of (I will be attempting this only after having a bootable backup of my current system)? I can use the command line quite well if necessary. Thanks in advance.