Win4Now - NICE LINK
As note in the link above by M$:
Administrators have the implicit ability to take ownership of any file even if they have not been explicitly granted any permission to the file. File owners have the implicit ability to modify file permissions even if they are not explicitly granted any permissions to the file. Therefore, you may have to take ownership of a file, give yourself permissions to delete the file, and then delete the file.
Opps I think most of us already assumed that you were trying to delete the file as the Administrator.
I'm watching this thread, because I really want to know what corrects the problem.