There are several global settings that can be managed in the Application Settings dialog. To access this screen, click the "gear" icon in the upper right of the top navigation bar.
The Desktop Client never saves XNAT account passwords, and always requires users to reauthenticate in order to log in.
Note: the Login screen of the application does not try to set a default XNAT – it lists the logins in the order that those XNAT accounts were last accessed.
Setting Application Defaults
Additional default settings can be configured in the "Application Defaults" panel.