Manage User Access - Enable/Disable Functions

To set user access rights go to Admin -> System -> Users.

Select the user and edit rights in the Module Access and User Rights For Company sections.

You can set page-specific access and assign user groups by activating the Advanced User Rights add-on. Create new user groups by going to Admin -> System -> Advanced User Rights. Assign users to groups by clicking the Edit Advanced User Rights link next to the Rights Group label when editing a user. You can include additional rights for specific users that aren't provided by the group they are in, as well as remove rights from users that are otherwise available to the user group they are in. Unchecked advanced user rights options for a person will not show in the interface when the user logs in. This gives you a way to streamline the user interface for people so the system shows them only the options they will need to use.