I am disposing of my old computer and wish to permanently and securely delete information/data from my hard drive. Are there any programs you recommend? In any case, how does one destroy a hard drive should there be no other reasonable choice? A Maherali
You can't really delete data from a hard drive. When you delete a file, the operating system just deletes the index reference to the file, so the file can often be recovered using an "undelete" program. To destroy the data, you need to overwrite the disk sectors with random data. Since the drive's read/write head may not always hit the same point on the disk platter, you need to overwrite the file sectors multiple times -- from seven to 35 times, depending on the importance of the data. There are lots of free programs that will do this: search Google for [hard drive eraser]. At the moment, I'm recommending Darik Horn's DBAN (Darik's Boot and Nuke). This uses a tiny Linux, so you can boot from a floppy and wipe any size hard disk without using the operating system(s) installed. There is also a Mac version. DBAN is used by the US National Nuclear Security Administration, it's open source, and it's free from http://dban.sourceforge.net/.
For even better security, remove the hard drive and wipe it with a degaussing machine as used by organisations such as the USA's National Security Agency. For ultimate security, put the disk platters in a bath of hydrochloric or sulphuric acid until the magnetic coating is eaten away (see http://www.whitedust.net/view.php?PageID=7).
