How can I enable a password using D-link 524, with my windows xp pc?

I’m looking to safe by encrypting to safeguard outsiders coming from opening my own method.Relating to basic guidelines but not any specifics with the way to achieve my personal target.I highly recommend you information.

http://technicallyeasy.net/2007/09/securing-d-link-di-524-wireless-router/
Here is the reason for this router set up

anticipation this specific allows.