Dell InspironXP Media Edition E1705

I have had this for almost a year.  All of a sudden I was being asked for a password to start up.  It automatically had my name on the first line but i was to put a password in the second one.  I never set a password to begin with.  At first i just clicked ok without a password and that worked!  Now it is insisting on a password.  I did the f2 and went to security.  There I re-set all passwords to none.  It still insist I should have one.  Why would this start all of a sudden and what do i do to get my laptop turned on?  Thanks for any and all help....RamblinRose