Question: I have been told that copies of all emails, sites, etc. are kept in secret files and folders in your computer(like the ones the police retrieve) and I was thinking of donating my current machine but an doubtful now. Is this true, and is there anything I can do?
Answer: It depends on what you mean by "secret". The files where your emails and web pages are held are specific and known locations on your hard drive. These files can be deleted before passing the computer on to someone else. It is possible to recover deleted files that have not yet been overwritten by other files since they are flagged as deleted rather than physically overwritten.There are programs available that will overwrite deleted files and make the data in them unrecoverable.
This article written by Stephen Chapman, Felgall Pty Ltd.