Security in vb2005

Question

I am looking for a way to create a secure user login account and I came about your article on active directory which I enjoy reading and would like to inplement in my application. My question is I am using XP Professional with MS Access 2003 as database and VB2005. Is it possible to implement AD Method in this situation since I know that AD works on servers?
Secondly for me to create a login data which method is the best? XML or Database?
Thanks Hope hear from you.
Kingsoh