Reset a Windows user password via a rescue CD

Download your rescue CD iso image

First of all download your preferred rescue CD, see iso images.

Create a bootable USB stick

Rufus is one of our favourite tools to create bootable USB sticks.

Another very easy tool is Ventoy. With Ventoy you can easily create a USB stick that can boot several OS by just uploading the iso images to the USB stick.

Reset Windows 10 user password

Boot from the rescue CD. At the end of the boot procedure you get a command prompt.

Now check the partition table with gdisk, an interactive GUID partition table (GPT) manipulator.

gdisk -l /dev/sda

It should find a valid MBR (master boot record). The output of the command should be more or less as follows:

(some information)
Found valid MBR ... Which do you want to use?
1 - MBR
2 - GPT
3 - Create blank GPT
Select the MBR that you want to use.

Now mount the Windows partition and move to the folder which contains the SAM (Security Account Manager) file.

mount /dev/sda2 /mnt

cd /mnt/Windows/System32/config

Consider that folder names are case-sensitive. Now enter the following command:

chntpw -i SAM

chntpwis a software utility for resetting local Windows passwords. It can edit user data and passwords, list groups and edit the registry.

Now you get the following choices:

1 - Clear (blank) user password
2 - Unlock and enable user account
3 - Promote user (make user and administrator)
4 - Add user to a group
5 - Remove user from a group
q - Quit editing user, back to user select
Select: [q]