Thanks. Works. However, the job keeps running in the background. Is the kill in the code one of the GNU Windows utilities?

no, kill is Perl's built-in, used to send any supported signal. Under Win32, it is described to "terminate the process identified by $pid, and make it exit immediately". Apparently, immediate exit is not guaranteed for unresponsive applications, so "taskkill /f" was required in your case.

The & Good Morning! confused me. Why is it there? Presumable a dummy activity, but why?

Correct, that "echo" part is kind of dummy; single/double (not important in this case) ampersand is to have several commands on one line, and serves no other purpose but to avoid checking for active tasks. Either I observe a "Good Morining!" even after Perl quit (child shell process was not terminated), or not.