much better to use the real management console to do stuff like this, gives you more granular control.
right-click "my computer" > click "manage"
expand "local users and groups" > Click on "users" > right-click on the account you want to edit > click "properties" > change whatever options you want.
Here is a good article for adding the few registry entries to make your password protected account log on automatically. http://www.logonexpert.com/freeautologon.html WARNING!
Be carefull editing the registery, double check everthing on each step.