Securely wiping and reinstalling the OS?

[stanw]

I have a Macbook Pro running Lion, and I have Lion on a USB drive. I need to securely wipe the Mac and reload the OS. I’ve never securely wiped a Mac.

1. Do I use Disk Utility on the Macbook Pro to securely wipe itself?
2. After being securely wiped, how do I get Lion back on the internal drive of the Mac?
3. Do I keep the USB drive plugged in while it is being securely wiped or do I insert it after being wiped?

*
Thanks.

 

[Weaselboy]

You don't need the USB key at all.

Just command-r boot to recovery then start Disk Utility and erase Macintosh HD. When you do that click on options and you will see a choice to do a secure erase. Be warned it can take a loooong time, particularly if you pick anything other than the first option.

When that is done quit Disk Util then click reinstall OS X. It will ask you for the AppleID you used to purchase Lion from the App Store, then it will download and install the 4.7GB OS.

 

[stanw]

Just to make sure I understand:

A.) I press command-r to boot to recovery
B.) It will then allow me to start Disk Utility and erase Macintosh HD

1.) I never purchased Lion from App Store, I got it on an Apple USB key from a physical store, so there is no record of me buying it with Apple. What do I do in this case?

2.) It is a 500GB drive in a 4-yr old Macbook Pro. Should I expect this to take a day? Two days to do a good secure wipe?

Thanks!

 

[Weaselboy]

Just to make sure I understand:

A.) I press command-r to boot to recovery
B.) It will then allow me to start Disk Utility and erase Macintosh HD

1.) I never purchased Lion from App Store, I got it on an Apple USB key from a physical store, so there is no record of me buying it with Apple. What do I do in this case?

2.) It is a 500GB drive in a 4-yr old Macbook Pro. Should I expect this to take a day? Two days to do a good secure wipe?

Thanks!

A) yep
B) yep

1) Is this one of the Air models that came with that USB key and Lion? If so you should be able to install Lion from the recovery partition like I described with no AppleID at all then. Alternatively, you can option key boot to the USB key and follow the same process. The advantage of doing it as I described from the recovery partition is you will get the latest version of Lion. If you use the USB key, you will get an old build then need to update through software update to the newest. Either way is the same end result.

2) If you lick the first option with a one pass wipe that will take a few hours.