This simple and brief tutorial will show you how to install the old Gnome’s Users and Groups management tool in Ubuntu 14.04 Trusty Tahr.
Ubuntu Unity does not have a graphical tool for managing users and groups out of the box. However, Ubuntu Software Center provides a package with a fully integrated set of Gnome System Tools, including Users and Groups.
Open Ubuntu Software Center, search for and install the package “gnome-system-tools” (without quotes):
Once installed, open “Users and Groups” from Unity Dash: