My wife's iMac died. It was a 17" model and died the death of all 17" iMacs with vertical lines down the screen. (This was mentioned here before.)

I replaced it with a 20" iMac really cheap from eBay. This iMac has proven to be unsatisfactory. It is an Intel iMac and from what I have been told there are serious incompatibility problems with this CPU and Flash videos. In addition, there was an incredible amount of software installed on the computer, at least 95% of it of no conceivable use to either myself or to SWMBO, and I suspect that, as on a Windows machine, installed "junkware" causes problems with stability and other problems as well. This computer has been an exercise in frustration from day one.

Back to eBay, and this I time spent money a bit more seriously and got a really nice 24" aluminum iMac. The seller was very accommodating, and at my request nuked and repaved the computer, sending it with just the operating system, Firefox and Chrome, Microsoft Office, Adobe Lightroom 3 and nothing else.

This has been a revelation to me. I really hate Apple products ("It's different from what I'm used to, so it can't be any good!") but this thing is pretty sweet. Connecting to the network printer, getting the flatbed scanner up and running... absolutely transparent and trivial. Maybe, just maybe, there is something to this Apple lunacy after all.

The new 24" iMac came originally from Apple with OSX 10.4 (aka: "Tiger") on it. The eBay seller updated it to 10.7 (aka: "Lion") and apologized because when he tried to update it to 10.8 "Mountain Lion" the Apple Store wouldn't do it because of something to do with him setting up the computer with SWMBO's account and the Apple store wouldn't let him update it using his account. He offered to refund part of the purchase price (I declined the offer) because of it. A nice guy.

Anyway... he included the original 10.4 Tiger disks with the computer. Finally, the question: Can I use those disks to nuke and repave the unhappy 20" iMac, or is it like Microsoft where the OS is registered to a single computer by CPU serial number and can't be put on another computer?

Oh, never mind. As always, Uncle Google has the answer:

Apple takes a different approach with its OS X software for the Mac. It intends to offer a modest new version every year. Installation is a 15-minute, one-click operation, and the price is piddling. For OS X 10.8, Mountain Lion, which came out Wednesday, Apple wants $20 — and you can install one copy on as many Macs as you have, without having to type in serial numbers or deal with copy protection hurdles.

I guess that answers the question. Or does it? Does that $20 get me a full nuke and repave option, or just an update to whatever OS is currently in the machine?

I have a pretty good idea how to nuke and repave a Windows computer (format the hard drive, put in the OS Installation CD and follow the directions) but what about an iMac? I'm guessing that I would insert the old 10.4 "Tiger" OS disk, power up the computer holding the "C" key and then see some options about erasing and zeroing (checks for bad sectors?) and then installing the OS. Then I could apply the $20 "Mountain Lion" upgrade?

Does that seem reasonable?

tanstaafl.