Tried it twice according to this guide. Both times it seemed to work, but after rebooting would not accept the password I reset it to. I even 'promoted' a user to Admin and that user didn't work either. Installing xp now.
From: 99% of gargoyles look like (MR_BASTARD)21 Aug 2012 21:07
I've not tried chntpw but have had success with ntpasswd which has an option to blank the password. They recommend doing this instead of changing the password which isn't guaranteed to work.