title: change the maximum number of open files in Windows
body: <p>I would like to know how I can change the maximum number of open files in Windows. Similar to ulimit command under unix. Under my c:\windows\system32, I cannot find the CONFIG.NT file, thus changing the file number in CONFIG.NT file won't work for me.</p>
  
  <p>The problem is I wrote a python script, in which I need to call subprocess.Popen(cmd, stdout=sp.PIPE, stdin=sp.PIPE, shell = True) 256 or 512 times. That means I need to launch 256 or 512 background processes. The script works fine whenever the number of launched process is smaller than 255.</p>