OS-X cannot be installed on this computer [Closed]

 jerry -
I recently upgrade HDD in my iMac 24" with 2.8GHz Extreme edition CPU.
Try to do fresh install of Leopard 10.5 on it and got this message OS-X cannot be installed on this computer.
Any idea? System can see and format new hard drive via Disk Utility, but no installation.

6 replies

Here are some points to consider if you still don't succeed installing OSX 10.5 Leopard or 10.6 Snow Leopard, even following the excellent step-by-step advice of the experts:

Remember that "Macintosh HD" or "My Mac" is NOT your internal hard drive - its only something on the drive. Now, if you try to install osx 10.6 (or 10.5 perhaps) and it says it can't install on "Macintosh HD", it probably means you simply have to reformat the DRIVE with the GUID option ticked. The GUID option will appear in Disk Utility ONLY when you choose to reformat the Toshiba or whatever drive. The option is NOT there if you try to reformat "Macintosh HD" because Macintosh Hard Drive is NOT a hard drive - lol ;)

The very last thing to do before reformatting your internal hard disk is to check that you really have backed up your disk on the external HD (borrow one if necessary). If you can't find the backup then don't reformat unless you don't mind losing everything on the internal hard drive. If you are using Time Machine don't be afraid if you only see a backup folder called Backups.backupdb The backup(s) are in there in another folder that might be called "Admin's Imac" - even if you're on a MacBook :o If there's more than one dated backup, its because you've backed up more than once - haahaa.

To summarise:
- "Macintosh HD" is not a hard drive, but Toshiba whatsit IS
(you cannot reformat "Macintosh HD")
- Your MacBook disk backup might be called Imac

I have just realised this after weeks of disappointment and wondering if my brain needed reformatting ;)

You might read that intel macs are always formatted using the GUID option when they have at least 10.5 installed, but this was not the case on my 2GHz Intel Core 2 Duo MacBook.

Anyway, my 80G Toshiba internal disk drive is now GUID formatted and the system updated from 10.5 to 10.6 Snow Leopard. I understand that Apple says you should stay on 10.5 for the Core 2 Duo processor, but all my useful and up-to-date apps are working fine, and I see no speed issues (yet).
I accept that some of my old apps (old games) which worked on the previous formatting and OSX 10.5 might no longer work.
I'd previously installed Snow from the bought update disk on an empty partition on a 250G eGo firewire/usb Iomega external drive - it didn't flinch when I asked it to install and it simply did what I asked without saying "I don't like this disk" or "you didn't previously buy 10.5 for this partition so I don't want to be nice"

I've had macs since 1984 and stayed with them because you don't need to be a genius to use them (and they don't get virusses unless you install a dubious application from the internet, and they never used to freeze, and never needed mending etc - even though you couldn't just go out and buy one from any old supermarket), so I got really really peeved when it didn't do what I wanted. Grrrrr
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I know the thread was old but the title is still appropriate :)

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Odds are the disk is not correct for the Mac

If generic Leopard may be to old if apparently new (came with computer) a accident may have happened and they are not actually the disks that belong to your mac (Big Box store Problem loose disks often)
Maby its an upgrade disk
Try buying mac osx 10.6 (snow leopard)
Its only $29 (one user)
and $49 for family pack (three users)
this same thing happened to me! why!?!