NirCmd Command Reference - closeprocess
Terminates the specified process, by closing its top level windows.
As opposed to killprocess command, closeprocess doesn't force the process to be closed
immediately. Instead, it send WM_CLOSE message to all top level windows of the specified process.
However, be aware that this command will not work on process with no user interface.
In the [process] parameter, you can specify the full path
of the process filename (e.g: 'C:\Program Files\Internet Explorer\iexplore.exe')
or the name of the process only, without the path (e.g.: iexplore.exe).
You can also specify the Process ID, by adding the '/' character as a prefix
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