The Defect User Desktop is only available if the Test Manager has chosen the Internal option in picking a Defect Tracking System in the Administration application.
The Defect User Desktop is accessed by non-Zephyr licensed users (like Developers, PMs, Business Analysts etc.) by typing in the following URL in a web browser:
http://<system_name_or_IP_address>/zephyr/desktop

Clicking on the Defect User, the login dialog is displayed and the username/password is customized from the Defect Admin application by the Test Manager, and is typically the firstname.lastname with the default password also being firstname.lastname. The user is given an opportunity to change that password on their first login.
The left side of the Desktop has a tool dock that lists all the applications that are available to the user. This entire tool dock can be slid to the left to make more room for application windows. It can be restored to its original just as easily.
The following application is currently available:
This application allows the user to search, view, add and modify defects.