protecting private information. How to erase harddrive

[stefancrs]

You can't be too careful. Somebody might want to read your CV.

I've never actually cared about these things. What could they find out that they couldn't find out anyway if they really want to, and who'd want to find out these things about me? Like. Uhm. My ICQ history. Oh no!

Adambomb337: Won't they have personal info about you anyway if they're to be able to buy a computer from you? Selling stuff anonymously could be a bit tricky.

[tetraplan]

If you're on OS X, a very safe bet is to install Norton Utilities. Apart from causing kernel panics when you empty the trashcan, it will carefully remove any data on your disk, wether you want it to or not (and usually, as these this go, it will do it when you don't want it to).

I was pretty sure I rm -rFfed the bastard two years ago. Damn.

Groet, Erik

[Sascha Franck]

A low level format will usually bring your HDD back to factory default state, erasing just everything completely. Most hard drive companies offer some LLF format tools. You need to run them from a boot floppy or CD.

I once crosschecked with some data recovery tools after performing a low level format on some Maxtor drive and they all found nada.

[Cabinfever]

I don't believe even a low level format will erase data completely. The best bet is the "eraser" utilty which does a 35-times write pass. Even then it's not certain. Physical destruction is the only sure way. That's what the Department of Defense does.
http://www.tolvanen.com/eraser/

[Doogle]

As stefan said, it's unlikely they'll get any real dirt on you. The average person doesn't really have anything that interesting.
And tbh, if the original poster really had something to hide, and suspected that the person they're selling the PC to was going to go to the effort of running a very low level scan on the drive, I'm sure they wouldn't be posting this question on KVR!
Unless they've got government secrets and suspect they may be selling the PC to a member of GCHQ/NSA or whatever