It is possible that Vista7.dll is no longer needed so I’ll look into it once I have some time in my hands.
As I wrote a few years before, I am not the original author of Vista7.dll so I can’t follow up on why it gets flagged as a virus. It’s also important to note that what some of these DLLs are doing will always get picked up by antivirus programs, since they are actually using mechanisms that antivirus programs are configured to pick up.
Can you share the scan from VirusTotal so I can have a look?
Finally, since Lineage 2 C3 is an old game, running it inside a VM is a perfectly fine way to play the game if you don’t want to worry about any custom DLLs.
Hope you have fun playing 🙂