Kodi’s subprocess.py

I’m running a python script at startup. All it does is it opens a .bat file. It works fine by double clicking it, but when I run it from Kodi I get

Code:
ERROR: EXCEPTION Thrown (PythonToCppException) : -->Python callback/script returned the following error<--
                                             - NOTE: IGNORING THIS CAN LEAD TO MEMORY LEAKS!
                                            Error Type: <type 'exceptions.WindowsError'>
                                            Error Contents: [Error 2] The system cannot find the file specified
                                            Traceback (most recent call last):
                                              File "C:\Users\firewater\AppData\Roaming\Kodi\userdata\series.py", line 5, in <module>
                                                p = Popen("Series.bat", cwd=r"C:\Users\firewater\AppData\Roaming\Kodi\userdata")
                                              File "C:\Program Files (x86)\Kodi\system\python\Lib\subprocess.py", line 710, in __init__
                                                errread, errwrite)
                                              File "C:\Program Files (x86)\Kodi\system\python\Lib\subprocess.py", line 958, in _execute_child
                                                startupinfo)
                                            WindowsError: [Error 2] The system cannot find the file specified
                                            -->End of Python script error report<--

This is the script:

Code:
import time
import os
from subprocess import Popen
time.sleep(2.5)
p = Popen("Series.bat", cwd=r"C:\Users\firewater\AppData\Roaming\Kodi\userdata")
stdout, stderr = p.communicate()

I’m guessing Kodi’s subprocess.py is interfering with the script? I don’t write in Python, so I really don’t know much about this – I more or less copypasted this from Google.

If anyone knows another way to call the .bat, that’s alright too, I just want it opened at the startup of Kodi.