There are an awful lot of Windows utilities that do this general sort of thing, depending on your full set of requirements. Do you just need to know when something changed? Do you also need to know what changed? Or who changed it? Are you talking content, or file size, or time stamp on the file? Do you only need to know when it changed at some later time, or do you need to take some kind of action when the change occurs? Will there be a user logged into the computer (so you could use a foreground program) or do you need a service that can start when the computer boots? How often do you expect the changes to occur, could there be bunches at basically the same time?
FWIW, last time I went through the process of looking I didn't find the perfect utility. I think the closest I came was called "The Folder Spy" which had a fairly primitive interface (and a green background!) but could take an action on detection of a change. Looking just now I see there was an update to version 2 a few years ago, available here
. I had found some prettier utilities that could run as a service but they didn't seem to be as reliable. I don't recall the one 4wd found, I ought to test that.
I appreciate the activity in this thread!