How to know which registry files to extract/use and how to do it?

[Chrushev]

So please correct me if I am wrong. But what I understand it is sufficient to simply pack (archive) the installation directory of a game for it to run no matter where its installed. But in addition to that we also need registry entries that get created on install.

Whats the easiest way to find which entries are needed and how to export/use them in my installer?

Thanks