Why port 1001 is occoupied by System? [duplicate]

I'm encountering an issue with port 1001, which is essential for a software my company relies on. This is result of netstat -ano:

TCP    127.0.0.1:1001         0.0.0.0:0              LISTENING       4

pid 4 is System (ntoskrnl.exe) and if I run taskkill /f /pid 4 (even in admin mode) I will get:

ERROR: The process with PID 4 could not be terminated.Reason: Access is denied.

Despite disabling and stopping various services, the port remains occupied. I've ruled out common HTTP-related issues since it's not port 80, 443, or 8000. How can I identify the specific application or service that is utilizing port 1001?