I started off right. I had everything prepared: a new 500gB hybrid drive, a fresh Time Machine backup, and an 8gB USB stick with the Mac Mountain Lion installer on it. I still managed to fail maybe 20 times over the course of two days booting from everything I could find, re-installing Lion onto the stick, backing up from Time Machine, etc. The closest I came was when I installed off the repair partition over a backup drive. The Mac started up its install process, but got stopped with a message that said that Apple was unable to confirm that my computer is authorized for an OS install. At least, that’s what I think it meant; it’s not a very clear message, and, no I didn’t write it down :(

This made me think that the problem was that I was trying to install the wrong version, although I was pretty durn sure that I had upgraded to Mountain Lion a few weeks earlier, having resisted the blandishments of Lion. Maybe Apple was confused, although I couldn’t see why. I installed the prior version of the OS on my USB drive. Nope.

And now for the answer. And it’s not going to make me look smart, that I promise you.

You see, kids, for Apple to verify my machine, it has to get onto the Internet. It turns out that if during the install process you give your Mac a choice of wifi hotspots to connect to, it picks an open one without asking for your say-so. As a result, it happened to pick a hotspot that requires a login on a web site, but there’s no browser available during the install process. Once I pointed the Mac to another hotspot, it was able to connect and authorize my machine, enabling the installation to proceed.

Sure it was dumb of me. But it’s also dumb of Apple to give us an error message that says that it’s unable to authorize, rather than that it was unable connect. (I also didn’t see a relevant message in the Installer log, but I may have missed it.)

Fortunately, each of the things I tried took a relatively long time to fail, so I was able to get a lot done while trying. Still, the moment of victory was definitely a forehead-slapper for me.