Manage Users from Command Prompt
If for some reason you cannot access the Control Panel window, you can manually execute these commands from the command line (DOS prompt) in order to perform common user account related tasks. These commands work on Windows 2000, XP, Vista, and 7.
Add a new LOCAL user:
net user username userpassword /ADD
Example:
net user John fadf24as /ADD
Add a new DOMAIN user:
net user username userpasswd /ADD /DOMAIN
Example:
net user John fadf24as /ADD /DOMAIN
Rename a user account:
wmic useraccount where "name='username' " rename new_username
Example:
wmic useraccount where "name='techblogger' " rename win7techblogger
Add existing user to administrator group:
net localgroup group_name UserLoginName /add
Example:
net localgroup administrators John /add