I recently answered a question about destoying the data on a hard drive before donating the computer (or selling the computer, selling the drive, etc.)
Before donating a computer or hard drive, you should wipe the hard drive to eliminate all your personal data. Just deleting the files or formatting the hard drive is not enough.
Use your favorite search engine to search for drive wipe or hard drive wipe. Be sure to note difference between programs that will wipe a drive and programs that will wipe a file. You will find links to a number of commercial, shareware and freeware programs.
Personally, when I wipe a drive, I use a DOS-based program called WipeDrive. It was the only tool I could find for a while. It is still available, but now there are free alternatives, too. I’m going to try this one pretty soon, though.
When you search for a drive wiping program, pay close attention to the description. If you want to wipe a drive, that is not the same thing as wiping individual files. It takes a program that will obliterate not only the data on the drive, by overwriting it with various values, but also it should obliterate the drive’s formatting and partitioning in the same way. File wipers might just ignore the empty space of deleted files — the same deleted file that had your credit card number or your checkbook data, for example.
I like the free, open source software from SourceForge.net. SourceForge.net is a “software incubator” for open source software and provides storage space, bug reporting & tracking facilities, and a version control system for maintaining control over changes to the source code — all for free to open source projects.
One such project is a disk wiper called Darik’s Boot and Nuke (http://dban.sourceforge.net/). On its web page, the description reads: “Darik’s Boot and Nuke (“DBAN”) is a self-contained boot floppy that securely wipes the hard disks of most computers. DBAN will automatically and completely delete the contents of any hard disk that it can detect, which makes it an appropriate utility for bulk or emergency data destruction.” DBAN is available both as an ISO image for burning a CDROM and for a floppy diskette.
The reviews I have read indicate that it is a good tool to have. I have downloaded and will have both the CDROM and the floppy versions available for my use.
According to their FAQ (Frequently Asked Questions) web page, as of version 1 (current is 1.0.6), DBAN can selectively wipe partitions and drives. Be sure to read the FAQ and the instructions. Early versions of DBAN were an “all or nothing solution” — you could not choose which drive to nuke (wipe) in a multi-drive system — it would “nuke” every drive it finds in the system.
I have not tried DBAN yet, since I don’t want to destroy all the data on any of my hard drives right now. My suggestion: unless you need to destroy the data on all the hard drives in the computer (which you would do just prior to giving it to some person or some organization), you should disconnect any hard drive that has data you want to save — and then boot DBAN. Of course, most people only have one hard drive in their computer, so that is not an issue for them..
Depending on the hard drive size and the number of overwrites you select, I’ve seen WipeDrive (the one I bought and use) take 12-16 hours at a medium setting. That was probably on a 40GB drive, so you need to plan accordingly. If you need DOD (Department of Defense) level data destruction, plan on leting it run for a long, long, time.
If you want a drive wiped, you should wipe the drive yourself. It’s your data; make sure it is safe.