If you want to use a new “Source” in the Windows event log, you cannot simply start to use a new text.
A new Event-log source has to be created first – BEFORE you start to use it.
Run this command as an administrative user to create a new source – here named “NEW SOURCE”
eventcreate /l application /id 100 /t information /so "NEW SOURCE" /d "Creation of a new Event Source"
To create a new “Source” in the Windows event log, you need administrative privileges