To preserve anonymity on a hard drive, physically destroy it. I think forensic teams can recover data even after it has been written over 7 times. For ordinary surfing, a clean install is the best way to "lose" old info. For state secrets and other confidential info, I would use a manufacturer's utility to overwrite the disk, then do a clean install, or follow any of the steps in the above signature! It seems that the ability to recover data is inversely proportional and as complicated as the value of that data. In other words, it's always easy to recover problems. A clean install is a good choice for a fresh start. A format would be sufficient "clean up" to give the computer away, under ordinary use.
Edited by Czarina, 06 September 2005 - 11:40 AM.