I need to know how do change my sony vaio lap to data so i can install windows XP?Thanx in Advance!!!

I just got a Dell Latitude D830 and it seems to have a fingerprint reader in between the two buttons for the mouse pad thing. I am not sure how to activate and setup the fingerprint hardware and software. Does anyone has any thought as to how:
1. Turn the hardware on?
2. What is the software that comes with this hardware?
3. How do I setup the whole thing to start working?
4. If I set this up, do I still have a way of accessing the computer with a password?
Thanks a lot you smart people!