You asked "what makes you think that a Perl script would be able to do it, if the system utilities can not"? The answer is because as stated in the original post, the commented line that sets the permissions works. It just replaces all the permissions with what I set and that is not desirable. I just can't figure out how to modify the existing permissions. I have security taken care of so that is not the issue. The issue is can Perl be used to modify existing NTFS permissions? I'm beginning to think it just isn't possible and that is certainly disappointing.