I'm giving an old iMac to my mom. She plans on keeping the current operating system (I can't find the disk to reload Tiger). I, at one point, had certain files that I would not like her to find out about. I deleted them, however, I'm worried that at some point she might take the computer in to get repaired or something and the files will be brought to light. Is that even possible first of all? Secondly, is there anything I can do to prevent that from happening?