To create a new user you need to go to the System Module > Person Register > New (from the person register you can either click on New or Duplicate an existing user and modify accordingly).
NOTE you need to pay attention to the type of user you are creating and to make sure you have the correct number of licenses for this user (either Named or Concurrent).
If the number of users and licenses do not match then the system will go into restricted mode.
If the new user is a named user you will have to create a mailbox for that user (from the Person Browse window, highlight the new user, open the operations menu and select create mailbox (you can also create a password from here).

HansaWorld Support