Probably the problem is about "configfile".
When you run a service, it run in "C:\Windows\system32", so if you have not an absolute path, you have to store your configuration file in there.
If you use dinamically path, instead, the user path is "C:\Windows\System32\config\systemprofile" and not "C:\Users\YourUser".
If you are not sure about the current working path, you can add this lines:
import os
import logging
logging.basicConfig(filename=r"Path\to\your\Log.log", level=logging.INFO)
logging.info(os.getcwd())
This will save a log file in a choiced path storing the current work directory.
If you are sure that the issue is related to configparser, I also suggest you to add a "try...except" to let start your service and to add a log write in the except, so that you can catch your error