To overcome this problem, you should open the program (probably it is minimized) and log off. After you did this, on the screen that appears, look for an option that says Remember password or Automatically login (
自動的にログインする). If you find one of the mentioned options, make sure to uncheck it. If the problem doesn't get solved, I strongly suggest to go to Start > Run > msconfig. In the new opened window, go under Service tab and make sure to select the Hide all Microsoft services from the bottom of the page. Next, go to Startup tab and uncheck this application. Clicking OK will save the selection and will reboot your PC. After the PC is rebooted, you won't encounter this behavior again.
To fix this problem, you can also uninstall the application and then install it again. To be noticed that in the installation process, you should uncheck the option that states "Start the program at computer start up."