Windows Explorer doesn't provide a way to change the original time stamp of the file, so how can we do it if we need to? My boss asked me how he can reverse the time stamp back for the files that he just copy and pasted to the different folder. So I did a Google on “Change the File Date”, which gives me a list of tools that let you be able to do it. I took a quick look and found FileDate Changer Version 1.1 is the most suitable one for my boss's case. It provides a graphic interface and changes the time stamp to the list of files, not just one at a time.
Download FileDate Changer v1.1 (20KB)