Add, delete and modify user accounts with CMD

Activate the hidden administrator account

net user administrator /active:yes

Change password for the hidden administrator account

net user administrator *

Activate the guest user account

net user guest /active:yes

Create a new user

net user John /add

Change password:

net user John 123abc

Delete a user account

net user John /delete

You will have to manually delete the user folder after.

Add user to the Administrators group (make the user admin)

net localgroup administrators John /add

Add domain user to the Administrator group

net localgroup administrators domainname\John /add