Clean hard disk and give away iMac 2007

If you want to do it yourself see the instructions in What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

Note: use the "If you can’t use Erase All Content and Settings" section as your 2007 iMac is too old for the "Use Erase All Content and Settings" section.

I don't know if an Apple Store near you will do it for you.

If you encrypted the disk with FileVault then there is no need to do anything else. Just get rid of it. The startup disk's data are utterly irretrievable without the FV encryption password. It cannot even be mounted. It's a brick.

Refer to Use FileVault to encrypt the startup disk on your Mac - Apple Support (archived). That would be the Support document most applicable to your reported OS X version (OS X 10.11). The current version of that Support document might not contain valid instructions for that system.

If you did not encrypt the disk, you can always do it now. It will take a long time to finish (days, probably), but it might be the easiest alternative.

laoxiao wrote:

Can I bring it to my nearest apple store (Bordeaux) and have this done there?

No, but they will accept it for recycling.

1) If you have the original Instal Disc Set that came with that iMac..? You can startup from Disc 1 and use the Utilities > Disk Utility to erase and reinstall the original OS X.

2) Because of it age and lack of support. I recommend Recycling it instead of cursing someone else with an unsupported iMac.

3) Then after it is erased, you can recycle it at your local Apple Store or E-Waste Recycler.

HWTech wrote:

….It is unfortunate that Apple's article which @FoxFifth linked is only for Macs using an SSD where a simple erase is sufficient to destroying all the data on an SSD. Unfortunately a simple erase does not work to destroy data on a Hard Drive unless the Hard Drive has Filevault enabled so that the data is encrypted…

Single-pass erasure works fine on hard disk storage from the 1990s onward, including on the HDDs in a 2007-era iMac

Multi-pass erasure is interesting for floppies*, and for hard disks old enough to have external head tracking. Hard disks with embedded servo tracking — pretty much every hard disk from roughly 1990 onward, and with all Apple disks associated with Mac OS X and later — are not prone to the slop that floppy disk tracking can involve.

The wrinkle here is with any sectors that were re-vectored and replaced due to errors, and those error sectors are where storage encryption is helpful. But for a one-pass erasure outside of military or classified data, the chances of any replaced sectors still containing sensitive data, and that data being recoverable, and that data being targeted for recovered, are approximately zilch.

The multi-pass erasure scheme was a common strategy back in the 1980s, with the Trusted Computer System Evaluation Criteria (TCSEC) included that and other requirements. Back in that era, hard disks that used optically-tracked striped stickers adhered on the side of the read-write head or other head-related hardware**, or some other external technique for track seeks and for head positioning.

Outside of floppies, all that head-positioning sloppiness disappeared whith embedded tracking.

And if the data is that sensitive and somehow wasn’t encrypted already or is somehow on a non-embedded-servo hard disk, stop trying to recycle the gear. Shred it.

*The chattering noise heard with the Apple Disk II floppy disk drives from thr late 1970s and into the 1980s was part of how the floppy disk head-positioning was implemented.

**I had to troubleshoot some old hard disks that malfunctioned when morning or evening sunlight shone into the disk drive and into its positioning hardware, particularly when the protective covers weren’t all properly placed. Or when lose machine screws dropped into the spinning fixed pack. Or other failures.

If you want to reinstall macOS 10.11 El Capitan for the new owners, then make sure to create a bootable macOS 10.11 El Capitan USB installer now while you still can do so using the instructions in the following Apple article:

Create a bootable installer for macOS - Apple Support

@John Galt has great advice for making sure the personal data stored on the Hard Drive is destroyed.....assuming the Hard Drive is still healthy. The other option besides enabling Filevault (must wait for it to finish encrypting) is to use the "secure erase" option in Disk Utility so that you write zeroes to the whole drive overwriting your personal files. Both options will take hours or even a day to complete....more if the Hard Drive is worn out or even failing.

It is unfortunate that Apple's article which @FoxFifth linked is only for Macs using an SSD where a simple erase is sufficient to destroying all the data on an SSD. Unfortunately a simple erase does not work to destroy data on a Hard Drive unless the Hard Drive has Filevault enabled so that the data is encrypted. A simple erase of an encrypted Hard Drive will destroy the encryption keys thereby destroying access to the data. Only the Erase Disk step in that article needs to be modified as suggested by @John Galt....all other steps can & should be performed as described in the article linked by @FoxFifth.

For what it's worth, if someone offered me a working 2007 iMac I wouldn't accept it. I do have a working 2007 iMac stored in our basement.

Why give a 2007 iMac, running macOS X 10.11 El Capitan? away?