Unable to erase HD running OSX

GlennM

Registered
Hello Fellow Forum Users and THANK YOU in advance for your assistance with this problem.

We have several old iMacs in our office that we would like to clean up before donating. One in particular is giving us trouble and no matter what we do, it will not allow us to run the disk utility to erase it.

I went so far as to remove the HD from the iMac and put it in an enclosure, so it's now an external HD. I tried plugging it into our new Macs, but because it's running an older OS, I cannot use the startup CD in the new Mac to erase / reinstall on the external HD.

Is it possible to install a newer OS over MacOSX? If so, should I just plug this HD into the newer Mac and use the newer Mac's disk utility?

Again, thanks for your assistance.
 

GlennM

Registered
p.s. - If I install a newer OS on this HD, it won't work if I reinstall the HD into the older iMac, will it?
 

DeltaMac

Tech
If you simply want to erase the hard drive, because of business or personal data, etc - then any method that you want to use that successfully erases the hard drive will be good. You COULD just leave the hard drive erased, and let whoever acquires that iMac decide what operating system they want. A Mac _should_ be passed on with a version of OS X that will run on that Mac - but not all used Macs get that attention (unfortunately true!). Whoever gets that old iMac might like to be able to use it. So - There's a good chance that the hard drive CAN have OSX installed, once you successfully erase it.
In your situation, I don't use the "erase" in Disk Utility. I suggest that you try changing the partition scheme. You have to select the "device" in Disk Utility (the line that shows the manufacturer's info) - and you will see the Partition tab appear. Click the "Partition Layout" dropdown, and change that to something else - like "1 Partition". Click the Apply button, and the existing partition setup would be removed, and the new one that you choose should appear in a few seconds. You would also make sure that the hard drive remains bootable (and installable), with the Options button. Choose the proper partition map for the iMac that you want to install OS X. A G5 iMac would need Apple Partition Map, and an intel iMac would need the GUID partition table - so you would select whichever is best.

OR - do you get an error message when you try to erase? (I/O error, or something else, leading to the conclusion that the hard drive is failing?)

In any event - can you tell us more details about how old the iMacs are (along with what OS X you are trying to install?)
 

GlennM

Registered
Thanks DeltaMac! I will reinstall the HD and try this and let you know what happens.

If you simply want to erase the hard drive, because of business or personal data, etc - then any method that you want to use that successfully erases the hard drive will be good. You COULD just leave the hard drive erased, and let whoever acquires that iMac decide what operating system they want. A Mac _should_ be passed on with a version of OS X that will run on that Mac - but not all used Macs get that attention (unfortunately true!). Whoever gets that old iMac might like to be able to use it. So - There's a good chance that the hard drive CAN have OSX installed, once you successfully erase it.
In your situation, I don't use the "erase" in Disk Utility. I suggest that you try changing the partition scheme. You have to select the "device" in Disk Utility (the line that shows the manufacturer's info) - and you will see the Partition tab appear. Click the "Partition Layout" dropdown, and change that to something else - like "1 Partition". Click the Apply button, and the existing partition setup would be removed, and the new one that you choose should appear in a few seconds. You would also make sure that the hard drive remains bootable (and installable), with the Options button. Choose the proper partition map for the iMac that you want to install OS X. A G5 iMac would need Apple Partition Map, and an intel iMac would need the GUID partition table - so you would select whichever is best.

OR - do you get an error message when you try to erase? (I/O error, or something else, leading to the conclusion that the hard drive is failing?)

In any event - can you tell us more details about how old the iMacs are (along with what OS X you are trying to install?)
 

DeltaMac

Tech
Good!
You can come back with more details about your iMac, too...
examples:
Which model iMac
Version of OS X that you try to install.
whatever other details you want to supply...
 

GlennM

Registered
Thanks for this, but the computer does not offer the partition option. The amount of time spent trying to deal with this is past the economical utility cost. I'm just gonna trash it.

Good!
You can come back with more details about your iMac, too...
examples:
Which model iMac
Version of OS X that you try to install.
whatever other details you want to supply...
 

DeltaMac

Tech
The "Partition" tab is NEVER offered, until you have actually selected the hard drive.
There's two lines displayed for each hard drive - one for the partition (there will be more lines if you have more partition), and one for the device (that line shows the manufacturer's info for the hard drive). When you select that device line, you'll see the Partition tab appear.

But, if you are giving up, that's OK, too...

Folks who post here often get asked for more info about their systems. Even if you have decided it's not worth the effort, someone else may find the info useful.
Sorry I couldn't be more help...
 
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