Default password on VISTA Home Basic edition?

My father in law is currently locked-out of his PC (dell inspiron) - he cannot remember the password. In fact, he cannot recall ever setting a password....is there any such thing as a default password?

If not, what can he do to remedy the situation?...and no, there is no password back-up disk/memory stick and there is no adminstrator account. The only options seem to be (i) use of a password cracking program (I have reservations about their safety) or (ii) reloading VISTA (which will be a right pain in the backside).

any other suggestions?

thanks

Simon