I have a iMac late 2009-2011 which was surplus to requirements. The hard disk failed and had to be replaced. Now I have a use for this iMac but I don't have an OS installed or to install.
The last OS that was installed was Mountain Lion but I don't have an installer disk and so how do I get an OS to install and what do I need to do?
I have a iMac late 2009-2011 ...
The exact model designation is relevant. Mid 2010 iMac and later models can use OS X Internet Recovery. Earlier models cannot.
If your iMac is too old to use Internet Recovery you need to boot from some other device—a bootable (USB, for example) installer or NetBoot.
How to create a bootable installer for macOS
Create a NetBoot, NetInstall, or NetRestore volume
Of course both of those options require another Mac.
The simplest way to determine if that iMac can use Internet Recovery is to try it. If it doesn't work and you don't have another Mac then you need that iMac's original, grey, Mac OS X Install DVD that shipped with mid-2011 and earlier models, and needs to accompany it from cradle to grave.
If you lost that DVD, then you need to obtain a retail, white, Snow Leopard Install DVD.
Apple no longer sells them but legitimate aftermarket sources exist. They are not cheap.
I have a iMac late 2009-2011 ...
The exact model designation is relevant. Mid 2010 iMac and later models can use OS X Internet Recovery. Earlier models cannot.
If your iMac is too old to use Internet Recovery you need to boot from some other device—a bootable (USB, for example) installer or NetBoot.
How to create a bootable installer for macOS
Create a NetBoot, NetInstall, or NetRestore volume
Of course both of those options require another Mac.
The simplest way to determine if that iMac can use Internet Recovery is to try it. If it doesn't work and you don't have another Mac then you need that iMac's original, grey, Mac OS X Install DVD that shipped with mid-2011 and earlier models, and needs to accompany it from cradle to grave.
If you lost that DVD, then you need to obtain a retail, white, Snow Leopard Install DVD.
Apple no longer sells them but legitimate aftermarket sources exist. They are not cheap.
Thanks,
fortunately this was a model that could use the Internet recovery. Some months ago I tried to do the internet recovery and it failed. Yesterday when I tried again it worked.
All good now thanks.
How to install an OS on a Mac where the HD was totalled and there is no backup
