I need to delete everything off a Hard Drive so I can sell it?

[SamIchi]

How do I do that? I know I can do a clean install, but just so everything is gone even the OS, how do I go about doing that? Thanks guys.

 

[Eidorian]

Boot off of the OS X and run Disk Utility to wipe the drive.

You can restart and eject the disc after that.

 

[Blue Velvet]

Re: Disk Utility. If you've got personal details, bank details etc. a 7x write zeros should suffice. It'll take some time though; leave it running while you're out for the day.

Boot off the OS X DVD/CD by holding down C as you restart the machine and run Disk Utility from the menu before installing OS X.

 

[teleromeo]

use the disk utility and the erase free disk space option

Depending on how secure you want it you can choose zero-out, 7-Pass erase or 35-Pass erase