Reinstalling OS X from scratch

[Eddy Deegan]

A young relative of mine recently bought a second hand 2009 iMac and when it boots up it begins the OS installation process but then fails to retrieve the OS installation from the app store with a message saying 'Item unavailable, please try later'.

Googling around a bit it seems that this is Apple's helpful way of telling you that the Mac is associated with a different Apple ID than yours. I have my relative's Apple account details but of course no idea what the ID associated with the original install was.

One online article recommended to log into iCloud using Safari (in the tools you get during the install process) and then to retry the installation but this failed. Then, the next time I tried it it's asking for the keychain password, which I obviously don't have.

Is there an easy way to simply nuke the whole thing and re-install the OS without all this hassle? I have my own Mac, a 2009 Mac Pro, which I can use to create install media etc. if that helps.

I've not used Macs for some time now and I'm finding the process somewhat frustrating, so if anyone has any input that would help I would be grateful.

[Arpangel]

Hi Eddy, I was in a similar position for different reasons with my 2012 Mac, all of what you described happened.
I'm sorry to be doom and gloom, but I ended up taking it to an Apple Store, where they imeditaly did a full, new install. But yours is older so that will probably not be an option.
I hope someone on here comes to the rescue, but I was on the verge of just binning mine, Apple seem to make all this so unnecessarily difficult.

[muzines]

I've never had a problem installing OSX, and never needed to connect to the App Store during the actual install process.

What version are you trying to install? If it's relatively recent, all you really need to do is (in generally) is run the installer, which sets up the install process, reboots, and starts the install for real.

If your OSX installer is small (like, 10MB or something), then obviously it is not the full disk image - when you run it, it will then download the necessary files from the App Store. If you haven't "purchased" that item on your Apple ID, then perhaps that's why it can't be downloaded, unless it's *really* old.

However, you can download installers that contain the full install image, and therefore won't need to download/retrieve any files from the App Store. I routinely download and keep these for old versions, so I can reinstall them, regardless of their status on the App Store.

So - what OSX version are you installing, and what's the size of the installer application?

[Jumpeyspyder]

(assuming you have another mac to create it on)
Easiest option would be to create a USB installer :-

https://support.apple.com/en-gb/HT201372

If you don't have that available - I can probably put one in the post

Ed

[Eddy Deegan]

I've never had a problem installing OSX, and never needed to connect to the App Store during the actual install process.

What version are you trying to install? If it's relatively recent, all you really need to do is (in generally) is run the installer, which sets up the install process, reboots, and starts the install for real.

If your OSX installer is small (like, 10MB or something), then obviously it is not the full disk image - when you run it, it will then download the necessary files from the App Store. If you haven't "purchased" that item on your Apple ID, then perhaps that's why it can't be downloaded, unless it's *really* old.

However, you can download installers that contain the full install image, and therefore won't need to download/retrieve any files from the App Store. I routinely download and keep these for old versions, so I can reinstall them, regardless of their status on the App Store.

So - what OSX version are you installing, and what's the size of the installer application?

Good questions. In all honesty, I don't know. The Mac boots to an installation menu offering to reinstall the same version of OS X that it had before (though it doesn't say what that is) or to override that with something else (but currently I have no installation media).

I stopped upgrading my 2009 Mac Pro somewhere just before El Capitan (Its running Snow Leopard or Mountain Lion I think) as it wasn't compatible with later OS versions, at which point I used it 'as was' for a while before pretty much relegating it to be a static file store when I bought a decent PC and went back to Windows. It's been switched off for most of the last 2 years or so and only gets used occasionally to pull a Logic project off for conversion to Reaper.

Based on what you've said I think the next thing to try is to create installation media from it and attempt to get that installed on the iMac. I was hoping there was an easier way but it doesn't look like there is.

Thanks Desmond!

[Eddy Deegan]

(assuming you have another mac to create it on)
Easiest option would be to create a USB installer :-

https://support.apple.com/en-gb/HT201372

If you don't have that available - I can probably put one in the post

Ed

Thanks Ed - that looks like a very useful article indeed. If I get desperate I might shout but I think I have everything I need here to do it from my own Mac Pro. As it's co-incidentally the same year as the iMac I'm trying to install OS X on that might reduce compatibility issues also.

[muzines]

Based on what you've said I think the next thing to try is to create installation media from it and attempt to get that installed on the iMac. I was hoping there was an easier way but it doesn't look like there is.

It seems you want to do a nuke and pave install. You'll likely need installation media I'm afraid, whether a disk (for really old versions like Snow Leopard etc), or an installer app, disk image, USB image, or partition etc.)

What OSX version do you *want* to install? A specific older version for some compatibility reason?
Or the latest OSX that the machine will support? (If you know what version that is, of course...)

[Kwackman]

If you have a internet connection on the mac, you can boot from the internet.
Key commands "Command" + "Option" + "R" at boot up.
You should be able to access Disc utilities (from on line, not your current HD) and erase your current drive, then install from internet.
Pretty sure it'll only let you install the latest version your machine can cope with.
I did this about a year ago, depending on your internet speed, it takes a while!
Good luck.

[ManFromGlass]

I’ve been fortunate here. I found a local Apple repair shop (not one of apples own stores) that keeps copies of every OS. I purchased for very little money an older os for an old tower and it worked fine. Maybe you’ll be as lucky.

[Eddy Deegan]

Based on what you've said I think the next thing to try is to create installation media from it and attempt to get that installed on the iMac. I was hoping there was an easier way but it doesn't look like there is.

It seems you want to do a nuke and pave install. You'll likely need installation media I'm afraid, whether a disk (for really old versions like Snow Leopard etc), or an installer app, disk image, USB image, or partition etc.)

What OSX version do you *want* to install? A specific older version for some compatibility reason?
Or the latest OSX that the machine will support? (If you know what version that is, of course...)

I'd like to get the latest OS X that the machine will support. My thinking was that if I got Snow Leopard or similar on it then I could upgrade it through the app store subsequently.

If you have a internet connection on the mac, you can boot from the internet.
Key commands "Command" + "Option" + "R" at boot up.
You should be able to access Disc utilities (from on line, not your current HD) and erase your current drive, then install from internet.
Pretty sure it'll only let you install the latest version your machine can cope with.
I did this about a year ago, depending on your internet speed, it takes a while!
Good luck.

I shall try this first... if it works that seems the most straightforward method! Installing over the Internet shouldn't be a problem here, fortunately.

Thanks to everyone for the help.

[fruitcake]

I normally install different Mac OSes on secondary drives, then make that my startup drive.
If you try a clean install in recovery mode (Command -R) and you still get a password prompt, that may be the easiest way to go. You would need a functioning Mac to download the OS install tho. (Download from the below links, it usually shows up in the Application Folder, not the Download Folder like everything else). Make sure you select the correct target drive when you install!)
You can try going to Disk Utilities and erasing the startup disk if you can access it in recovery mode then reinstalling. I don't know if a 2009 iMac is supported with recovery install.
There are a lot of good webpages on this with a little searching.
This may help:
https://www.imore.com/restoring-high-si ... -you-think
or this
https://www.macworld.com/article/340457 ... esort.html

Apple hides old OSes in the Apple store,

Here's a link to the High Sierra Installer:
https://apps.apple.com/us/app/macos-hig ... 4741?mt=12

If your 2009 iMac isn't compatible, Here's a link to El Capitan:
https://apps.apple.com/us/app/os-x-el-c ... 5434?mt=12

Good Luck!

[Eddy Deegan]

Thanks all, I finally got this thing up and running although it took ages. It didn't seem to recognise any keys-held-while-booting combinations except for one (see below).

Turns out it won't run anything later than El Capitan without hacks, so I've gone with that. I ended up creating the El Capitan install media on USB using my Mac Pro, but then discovered the iMac wouldn't recognise it from the recovery boot. There was bad language.

After a bit longer than it should have taken I finally got it to work by discovering you can hold the option key down during powerup to select a boot drive. From there it found the USB media and allowed me to install from it though that boot menu is, I think, bugged (the mouse would only go vertically up and down and not side to side, so I had to use the arrow keys and 'enter' to select the drive as I couldn't click on it.)

Garageband won't install on it and Apple don't provide old versions as far as I can tell (why on earth not?) but but it seems very happy with Reaper and Dexed for starters which should keep him occupied for a while.

I know it's an old machine but the whole experience was very frustrating, Apple docs were of almost no help at all and I'm reminded why I left the Apple world! That said, I'm really happy to have been able to send him a message that it's ready for him to use.

Thank you all again for your help and may you all have fewer issues with all things Mac than I seem to have had

[Howdy Doody Time]

My wife gave me her macbook air when she got the latest phone. I also have two of her old iPads. Unfortunately she can't remember the passwords for any of these things except the Air. It is always prompting me to log into App Store or iCloud neither of which are available to me due to forgotten passwords. I get that some people respect all this security and have had occasion to be thankful for it, but criminals and carelessness aside, it really is intrusive, and has crippled some hardware and renered others unusable. Mind you, I'm using Windows a lot more now, and it's not blameless either - Last night I wanted to go to bed, but my Windows laptop had other ideas, warning against turnung the off until updates, then configurations were completed.