The user can be enabled to reset its password by itself when he connect to the thin client.
On "Imprivata OneSign" window (accessed via "Terminal Properties" on thin client) you can flag "Allow Self-Service Password Reset" to allows users to reset their password.
If the option is enabled at thin client startup the "Self-Service Password Reset" button is showed on the OneSign Login window.
Clicking on the "Self-Service Password Reset" will open a browser window that point to the correct OneSign server that permit the user to reset his password.
