Search notes:

hotplug.dll

hotplug.dll can be started in cmd.exe with control.exe to bring up the the Safely Remove Hardware applet (which might be used to eject a USB drive) 
C:\> control hotplug.dll

See also

Apparently, this «applet» can also be started with rundll32.exe: 
rundll32.exe shell32.dll,Control_RunDLL hotplug.dll

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