chntpw is a Linux utility to (re)set the password
of any user that has a valid (local) account on
your WinNT or Win2000 system, by modifying the
crypted password in the registry's SAM file. You
do not need to know the old password to set a new
one. It works offline (i.e., you have to shutdown
your computer and boot off a linux floppy disk).
The bootdisk includes stuff to access NTFS
partitions and scripts to glue the whole thing
together. This utility works with SYSKEY and
includes the option to turn it off. A bootdisk
image is provided.