Bleach for my hard drive.

[G]

I'm selling my computer to help finance my NZ trip. I've had it for a few years, and the hard drive is full of personal stuff that I don't wish to share. I've heard that Re-formatting the hard drive doesn't completely erase all of it's contents, and it's possible to extract previously stored info from a freshly reformatted hard drive.

Is this true, and if so is there a better method of cleanup?

[MOHSHSIHd]

VHS/tape eraser industrial strength magnet

[Mechmaster]

A zero format would do it (including the boot sector). Basically, this process overwrites the entire drive with zeros, then deletes everything.

[Meathelmet]

You can find some freeware from the net that mechmaster described.
They write the hd full of random chipher.

But if you are having something top secret on the disc (you and the sheep)
destroy the disc physically.
Some firms (especially the inet security and goverment) have managed to read data from the disc even after 5 times of chiphering.

[phUnk]

Alternately, you just uninstall all your apps (except for the operating system) and your personal files, then fill up your hard drive (by copying a few large files/folders repeatedly). Finally erase everything so the buyer doesn't get a harddrive with 100's of copies of Girls.Gone.Wild.College.Edition.III.avi

[Sphinx]

Selling a computer that you've had for several years? What are you getting for it? $10?

[focus]

what makes you think some random person who buys your computer is at all interested in your personal shit?