On my T620 Thin Client, I have multiple people using the device. However, if they fail to logoff, how do I switch users (without restarting)? CTL/ALT/DEL doesn't work. It just goes back to the users login and askes for password, but the only option is to Restart or Shut down. How can I 'switch users' or at least get to the normal login screen where I have the option to pick 'other' user?