I want to sell my Mac Book Pro laptop, but I need to erase hard drive?

Question

I want to prepare my mac book pro for a safe sale, and not have to worry about somebody getting into all my stuff. How can I erase the hard drive?

Please be specific, I am not extremely computer literate and will need to know step by step. Thank you.

Answer 1

It isn't true that once you delete a file it is gone. When you delete a file, your computer actually deletes the information that points to the file on the hard drive so that the system no longer sees it and can reuse the space if needed. The file still remains you just can't see it - but with the right tools they are recoverable.

If I bought your macbook from you and all you had done was delete your home folder I could, without a doubt, recover the majority of your files including you browsing history and any documents, images or personal files you may have had. And remember, to someone trying to steal your identity or credit details, you are a very nice target - you are selling your laptop because presumably you have enough money to buy another one and that means you've either got money or you get credit!  Often, the cost of purchasing a second hand computer is far far less than the amount that an be stolen from you or in your name by a criminal.

What you *really* need to do is securely wipe the hard drive and reinstall the system. By securely wiping the hard drive, you'll be writing random data over the top of the entire disk meaning that if any files (or file fragments remain) they are obliterated and cannot be recovered. To do this you will need your original install disc.

Instructions

1) Backup all the files and folders you want to keep

2) While your computer is on, insert your original install CD

3) Restart your machine, holding down the 'c' button so that the machine starts from the CD

4) Once the system has started, you will be presented with the welcome screen - move onto the next screen until a menu bar appears at the top of the screen

5) In the menu, select Utilities > Disk Utility

6) On the left hand side of the disk utility, you should see the hard drive, with the volume name beneath it. You should select the first drive in the list (the one that starts with it's size rather than it's name)

7) In the right hand pane, select Erase

8) Select Volume Format: Mac OS Extended (journaled)

9) In Name, give the drive a name... this can be anything but best to use a single word with no punctuation - I use MacHD

10) Click the "Security Options..." button

11) An options sheet will appear, select "7-Pass Erase"

12) Click OK

13) Now click "Erase"

14) And in the dialog box, confirm by clicking Erase again

15) Go and grab some dinner, this will take a while

16) Once the erase has finished, quit the Disk Utility from the menu bar 'Disk Utility > Quit'

17) Continue on with the install and install a base system.

18) Once the install is complete and the laptop restarts, it'll present you with a setup dialogue (after a funky video) but you should leave this so that the new user can set up the machine. You should just shutdown the machine by selecting 'Shut down...' in the apple menu (top left of screen)

Let me know how you get on - any problems, then drop me an IM or an email

Best

Ross

Answer 2

Macs are pretty good and secure. Once you have deleted and then emptied the trash, it's unrecoverable.

Open your Macintosh HD icon (top right) select your personalname folder and also documents folder and drag to the trash.

Open the trash and click empty while holding down option key.

You might want to go through hard disk and see if you saved any files elsewhere to delete, but that should do it. :)