[kazinator]

So in the present example from Raymond Chen you need the loop for a similar reason.

The binary .exe program which the script is trying to delete is the one which created the script and launched it. So that means the .exe is still running at that point and cannot yet be deleted. Lauching the script indicates "I'm about to die", not "I'm already dead". The script cannot delete the .exe until the .exe terminates. Without some event to indicate that, you poll.

The script knows it can delete itself, so it tries that only once.

If a handle could be attached to the process, then the script could do a WaitForSingleObject on it; that would be the prim and proper way.

It doesn't seem worth doing; the chances are low that the process cannot terminate within 20 seconds of launching the reaper script.