Since the other questions have been so well answered I'll answer this one. There is a ISO called Windows Rescue CD which is a customized Linux distribution that will allow you to edit/clear the passwords. If the user had encrypted files clearing the password will render them unusable.
The only drawback to it was that if the NTFS filesystem needed to be checked it would only allow you to view data on the drive and not change it.
I tried locating the one that I use but as of yet can't find it. I did find another CD that has similar capability:
http://trinityhome.org/Home/index.php?wpid=1&front_id=12
Clearing passwords has made repairing computers much quicker (don't have to ask what it is).