@echo off
set count=0
:loop
set /a count=%count%+1
echo Count %count%
@echo on
perl -e "if ($pid=fork){Win32::Sleep(0); kill(9, $pid); Win32::Sleep(0)} else {sleep 1000}"
if errorlevel 1 goto exit
@echo off
goto loop
:exit
ECHO.%ERRORLEVEL%

##</code><code>##

The outcome of kill on a pseudo-process is unpredictable.
It depends on the timing in the Windows operating system.
Code that has worked, suddenly can fail, resulting in errors which are difficult to find.