As I encountered the similar problem before, so I wanna answer it from my experience. There are two types of PDF password: user password and owner password.

A user password means that you can not open the PDF file before typing on the right password. An owner password protects the PDF file from being copied or printed.

The right way you need to do is to remove the restrications. A right PDF Password Remover can help rip the password easily.

Last edited by shabbir; 31May2010 at 18:06.. Reason: Removed