text: When dealing with personal computers, other than the manufacturers label on the front of the machine that may have the date the hardware was assembled at the factory, there are no hidden locations containing a date that Windows 98 or Windows XP was loaded or when a hard drive may have been changed.\n\nThere are entries in the registry that contain the date that the operating system, Windows 98, Windows ME, Windows XP, etc.) was installed, but their integrity is not guaranteed because a correct date is not required for the machine to run; you can change the date and nothing will happen.  The same is true for a file as well.  You can very easily find programs that will let you change the date on a file; creation, last accessed or changed.  You can change some settings so that the last accessed date is not tracked.  You can back up a file and use the current date when you restore it.\n\nThere is no easy way to tell when someone was on your machine, especially if there is no password required when you log in or if you leave your machine on all the time.\n\nI could be way off so if you could tell us what you are trying to do, maybe we could give you another road to try.