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.