Question: I have a old computer that I want to dispose of but would like to remove all files etc before I do this. How can I remove every thing? Don't want personal data out there.
Answer: A number of my friends have found that opening the case, removing the hard drive, and giving the hard drive a few good hits with a hammer is the most effective way. Alternatively if you are giving the computer to someone else to use then there is security software that you can get from the web that will overwrite the supposedly unused portions of the drive multiple times with random data so if you run such software after deleting all of your data then it should make the data completely unrecoverable.
This article written by Stephen Chapman, Felgall Pty Ltd.