It used to be a paid program, but they now provide it for free. It works for Windows NT, 2000, XP, 2003, 2007, Vista, and Windows 7.
I use this frequently. The easiest way to do it is boot from it and simply select the user that you want and check the box that says "Password is empty.
Kalpesh Chavan
To reset Password of any user
use following command
net user <username> <password>
but you require administrative privilege
we don't require current password
I also use the Offline NT Password disc, but have had many times where it didn't work, only to end up using PCLoginNow anyhow. I keep both of them (and Ophcrack) on my bench, but usually use PCLoginNow because I know that one loads fast and works almost every time.
If that one doesn't work, the other ones usually won't work, either.