scfg.exe (Windows) ghost instances are possible

When closing SCFG ungracefully (e.g. using the red 'x' icon or the "Close window" popup menu option from the taskbar), can leave an invisible instances of scfg.exe running:

C:\>tasklist | findstr scfg
scfg.exe                     36668 Console                    1     34,216 K
scfg.exe                     36088 Console                    1     34,048 K

taskkill (or similar) must be used to terminate them, e.g.

C:\>taskkill /f /im scfg.exe
SUCCESS: The process "scfg.exe" with PID 36668 has been terminated.
SUCCESS: The process "scfg.exe" with PID 36088 has been terminated.