here is a process kill function for windows:

<?php
function win_kill($pid){
    $wmi=new COM("winmgmts:{impersonationLevel=impersonate}!\\\\.\\root\\cimv2");
    $procs=$wmi->ExecQuery("SELECT * FROM Win32_Process WHERE ProcessId='".$pid."'");
    foreach($procs as $proc)
      $proc->Terminate();
}
?>