Reset a Windows user password from an Ubuntu live CD

Things to be aware before starting

  • Make sure that secure boot is disabled and the Windows partitions aren’t encrypted.
  • Make sure that Windows is properly shutdown. You can do this by either pressing Shift before clicking Shutdown or by executing this command shutdown /s /f /t 0 in the terminal.

Boot into an Ubuntu Live CD

If it doesn’t boot or you can’t see the disk with Windows check the following:

  • Is the SATA option set to AHCI instead of RAID?

Enable all the repositories

sudo apt-add-repository universe restricted multiverse
sudo apt update

Install chntpw

sudo apt install chntpw

Mount the Windows drive and navigate to the SAM file

It doesn’t mather where you mount the drive you just need to know where you mounted it. Afterwards navigate to the SAM file e.g.:

cd /media/ubuntu/some_volume/Windows/System32/Config

List all the accounts in the SAM file

chntpw -l SAM

Choose the user and reset the password

The following command will select the user localadmin, unlock it, reset the password to a blank string and then quit the application.

chntpw -u localadmin SAM

Reboot and login

Before you boot back into Windows make sure that you reset the SATA option back to what it previously was. Otherwise Windows might refuse to boot. Now you should be able to boot back to Windows and login.