Is there a log kept of all the previous "date modified" dates for
regular files? A file was altered, and I am trying to find out when.
Since it was saved earlier today, I cannot find out the previous "date
modified" occasion. Also, if it was renamed, can I find out the original file name?

Although it is possible that a journaling type filesystem could
potentially do this, I'm not aware of any journaling file systems that
keep track of that sort of thing beyond the times that their journals
are committed for permanent changes.

A Version Control System, such as CVS, or the more modernish
Subversion software, has no problem keeping track of this sort of
thing, as well as many other things, including the changes, and the
ability to roll back a file to just about any point in history.

Without further information, I'm guessing that you're using Windows,
and I'm fairly certain that even with NTFS, you won't get information
beyond what is already there.

I am using Windows XP. Can I view it though dos or something?