reset Windows admin password, promote user to admin:
'''
sudo apt-get install chntpw
cd /media/...mount.../...sys.../Windows/System32/config
sudo chntpw SAM
'''

If your Administrator account is locked—and it is by default—type 4 at the prompt and press Enter to unlock it. Type y at the confirmation prompt and press Enter to confirm.

You’ll have to run the sudo chntpw SAM command again to get back into the program. Type 1 and press Enter at the prompt to clear the Administrator’s password and make it blank. Type y at the prompt and press Enter to confirm again. Important: Do not use the change password option here, as it could cause problems.

You can now log into Windows with the username Administrator and a blank password. From there, you can open the Control Panel and reset other user account passwords.