I have recently purchased a laptop and am going to sell one of my pcs
on ebay.  I am going to sell it without an OS.  I need to know how to
completely erase the hard drive (free pc programs, or built in
programs).  I have heard stories of people seller their pcs thinking
they had erased the info when in fact they havent.  Thanks!!

Hello jimmy!
The best way erase all data on your hard drive without possibility of
recovery is by performing a "low-level" format of your drive. Check
with your hard drive's manufacturer page to see if they offer a low
level format utility. In the following page you will find links to
hard drive's manufacturers web sites:

Hard disk low level format utilities
http://www.disk-utility.com/hard-disk-low-level-format.html

In case you're not able to use such an utility, I've located some
shareware programs that are specifically designed to erase files or
the entire hard drive without possibility of recovery. Check out the
following page:

LSoft Technologies, Inc.
http://www.lsoft.net/products.html

Among the products they offer, the one that probably most interests
you would Active@KillDisk:

Active@KillDisk Hard Drive Eraser Secure Formatting
http://www.killdisk.com/

The free version of this program can erase your first hard drive
letter; however, if you have more than one partition and want to erase
the data in all of them, you will have to go for the Professional
Version, which costs $29.95

Another shareware program that wipes all info from a hard drive can be
found at:

East-Tec FormatSecure
http://www.east-tec.com/formatsc/index.htm

You can learn more about Low-level formatting in this page:

Low-level formatting, Zero Fill and Diagnostic Utilities
http://www.pcguide.com/ref/hdd/geom/formatUtilities-c.html


I hope this information is useful to you. If you have any doubts,
please request a clarification; otherwise, I await your rating and
final comments.


The Google search terms I used were
"wipe your hard drive"
erase wipe data recovery freeware
low level format


Best luck!
elmarto

Thanks!! Very fast answer.  Exactly what i needed.

Here is a very interesting article about students who bought hard
drives on ebay and recovered other people's info:


"Old hard drives yield data bonanza"

http://news.com.com/2100-1040-980824.html

More of an FYI for ya - has more links to solutions as well :)

jimmyjrosu,

Be warned! elmarto's answer has given you many choices.  If it falls
to a good, hard core "hacker," an oridinary low level format doesn't
gurantee "complete" unrecoverability.  To a minimum, you should always
choose a program that can perform to the DoD 5220.22-M or 5200.28-STD
standards, a.k.a. DoD Wipe.  Gutmann's data distruction is arguably
the best, which "cleanses" with 35 passes.

Some helpful information regarding how each method works:
http://www.killdisk.com/notes.htm