A utility that can edit windows registry, reset user password, promote users to administrator by modifying the Windows SAM. Boot target machine with live cd like Kali Linux and run with elevated privileges. More information: https://pogostick.net/~pnh/ntpasswd.
chntpw -l path/to/sam_file
chntpw -u username path/to/sam_file
chntpw -i path/to/sam_file