I read about the NTPasswd offline password reset utility a few times in the past, and always wanted to give it a try to see how well it worked. Recently the need to do so came up on a Vista machine, and I noticed a few important behaviors than I wanted to document for those that may have to use this tool. I also tested on XP with the same results.
In regards to local user accounts, NTPasswd has 3 main options 1) Blank an account’s password 2) Reset the password to one of your choice 3) Escalate an account’s privileges (add to local admins group). These are the behaviors I found:
Reset the Password: Doesn’t work, it appears to, but after rebooting unable to log in using either new or old password. Also appears to corrupt the account (logging in with another admin account and attempting to change the original account’s password fails). Have to do a System Restore to fix.
Blank the Password: This works great; no problems.
Add Account to Administrators Group: This works, but it appears to break something in either the registry or SAM file. Afterwords using either the Compmgmt.msc snap-in or the net user & localgroup commands, it is not possible to view the Administrators group membership, or to add / remove any further members. I had to do a System Restore to fix this.
NTPasswd does give a warning stating that resetting a password or escalating privileges can have flaky results on XP and Vista, so it’s not as if these results are entirely unexpected. This is still a great tool, just make sure you have a System Restore available if you do anything other than blanking a password. Let me know if you’ve had different results.
Filed under: Utilities, Windows | Tagged: NTPasswd, Offline Password Recovery, Password Recovery, SAM Database, Vista, Windows Vista

What do you mean by blanking a password??
By blanking a password I mean the existing password is changed to blank, or nothing. So you can log in as administrator without supplying a password.
well, blanking a password is what we need no? ur able to login in and whatever …the client that forgot his password will be happy :)
I recommended this to my brother in law after he forgot the password to his vista box. He’s very, very happy now. The ntpasswd instructions told him to just blank the password, and that’s all he needed.
Note the link to NTpasswd has changed to
http://pogostick.net/~pnh/ntpasswd/
Once you sort this problem, the best thing to do is set up another user account (with Admin rights) with either a simple to remember or no password.
That way you will be able to log-on using that account and reset the password for the account you have forgotten the password for.
Or you can goto Microsofts support website and create yourself a password recovery disc at the same time you change the password and you will never have this problem again.
http://windows.microsoft.com/en-us/windows-vista/Create-a-password-reset-disk
Remember though if you dont have a password recovery disc and you have forgotten the password for the ADMIN account (and that is the only user account) you will probally have to re-install windows