First you need to know which file time you mean.

You might also want to give this link a read and then let us know more specifically what it is you're trying to do as there may be a better method or tool to do it. Most of us love KiXtart but sometimes there is a better tool to do things.

http://blogs.msdn.com/b/oldnewthing/archive/2011/10/10/10222560.aspx