I had to restart. It looks like it's taking off from where it failed, but of course I won't know until the whole download finishes and I try to install

A year.

Cozmique Computer Reality....

even though

Applications > Install OSX Mountain Lion.app > Shared Support > InstallESD.dmg

is nominally only 4.35GB. Whatever. Anyway, lots of people have trouble unless they do this, and so did I. So I went out and bought myself some DL (dual-layer) 8.5GB DVDs to be able to do this, and now it looks like I've successfully burned it and verified the burn, cuz it ejected and when I reinserted it in the optical drive, a Mac OSX Install ESD finder window opened to show Install OS X Mountain Lion.app and several folders

But, also, I am learning what lying asshat copycats most of the people posting on the web are

You read "X is really simple! All you have to do is blah blah blah!" And then you try it and it doesn't work

So you look for other instructions and you find word-for-word the exact same useless effin instructions on a gazillion other websites

And then finally you find one where somebody put in the comments field "Disk Utility won't make a usb stick from this dmg unless you mount the dmg before trying to use the Disk Utility Restore operation" and the frickin copycat asshat answers something like "Thanks!" And you finally find one where somebody put in the comments field "Actually I always got a Disk Utility Burn error with a standard 4.7GB DVD, so I had to use a 8.5GB DVD-R DL. And it seems like maybe most of the folk posting all these helpful instructions have never ever tried them

That means I should get Lion reasonably up to date

That is projected to required at least 10 hrs of downloading for 2.13GB of upgrade

10 hours of download/install time, and now I'm onto the second update/install round on Lion, which will take another couple of hours

my Mountain Lion install/upgrade disk

and run a time machine backup!

You'll have better luck if your internet connection is faster than mine, and if you've kept your machine up-to-date and backed up, because nearly half of this is me updating Lion on a portable machine I haven't used recently and that I've been very negligent to back up

I won't have to re-do the 20 hr download (if my disk works) cuz that's why I made the disk -- but I have several other machines that are gonna require at least the 10 + 2 hr double download update

My main machine, when I get around to doing it, after I'll ironed out the bugs on several others, should go reasonably fast: I've kept the software up-to-date and everything backed up