man chntpw (Administration système) - utility to overwrite Windows NT/2000 SAM passwords


chntpw - utility to overwrite Windows NT/2000 SAM passwords


chntpw [options] <samfile> [systemfile] [securityfile] [otherreghive] [...]


This manual page documents briefly the chntpw command. This manual page was written for the Debian distribution because the original program does not have a manual page.

chntpw is a utility to view some information and change user passwords in a Windows NT/2000 SAM userdatabase file. It is not necessary to know the old passwords to reset them. In addition it contains a simple registry editor (same size data writes) and hex-editor with which the information contained in a registry file can be browsed and modified.


Show summary of options.
-u username
Username to change. Default is Administrator
List all users in the SAM database.
Interactive: list all users (as per -l) and then ask for the user to change.
Registry editor with limited capabilities.
Use buffer debugger.
Show hexdumps of structs/segments (deprecated debug function).


chntpw sam system
Opens registry hives sam and system and change administrator account. This will work even if the name has been changed or it has been localized (since different language versions of NT use different administrator names).
chntpw -u jabbathehutt mysam
Prompts for password for jabbathehutt and changes it in the mysam registry file, if found (otherwise do nothing)


If you are looking for an automated procedure for password recovery, you might look at the bootdisks provided by the upstream author at

There is more information on how this program works available at /usr/share/doc/chntpw registry works, what are syskeys and some other issues.


This manual page was written by Javier Fernandez-Sanguino Peña <>, for the Debian GNU/Linux system (but may be used by others).