The client can not be restarted, even if the notes.exe and nlotes.exe tasks stopped in the task manager. Only rebooting helps, but that is not a user friendly solution. This occures on Lenovo laptops. How to restart the client only? Is there any additional task should be stopped?
Some people will suggest KillNotes to you, but this can cause corruption.
The better way is to go into the notes folder and run the following command.
It should remove all processes that will stop it rebooting.
Alternatively on the start menu you can use the following.
Lotus Applications -> Support -> Collect Lotus Notes diagnostic data and exit Notes