Here's the one I've always used, and recommend whenever someone asks:
Austrumi (v0.9.2 - December 2004)
Austrumi is a Linux bootable ISO image for recovering NT passwords and other cool tools and methods, sized for Business Card size CD media (50Mb). It allows you to change any password, including that of the Administrator, on a partition occupied by Windows NT, Windows 2000 or Windows XP. Simply boot the CD and when you get to the initial boot prompt, type:
boot: nt_pass
This will launch a console utility that will detect Windows partitions on the hard disk and provide you with a menu to modify any user or Administrator passwords on the Windows system. It will even give access to the Windows registry for recovery purposes. Quite a handy utility to keep in your wallet (AUSTRUMI is small enough to fit on a business card-size CD) if you are unfortunate enough to having to deal with Windows machines in your line of work.
Read more at
http://sourceforge.net/projects/austrumi
Download links:
Austrumi v0.9.2 (ISO file, 50.9mb)
[Reposted from
here]
PS: Don't let the word "linux" put you off, it really is just as simple as the instructions make it sound, less than a five minute process with instructions every step of the way.