To remove your certificate from the browser certificate store when you log out of IDTool, click the 'Advanced' button in IDTool, then in the 'Advanced Functions' screen, click "Logout and remove certificate." Your certificate will automatically be removed.

From a security perspective, it is not necessary to remove Roaming Certificates from the computer after each use. However, if a computer is used by multiple people with different digital certificates, it may be confusing because browser selection boxes will show all the certificates stored on the computer.