[@lyrics Member 16 years, 1 month ago]

You put it in the folder that you want your forum index to be, most people usually make a folder called /forums/ or /forum/ unless you want it to be as the root index of the whole website (for example if the main site itself is the forum).

Another alternative is to make a subdomain like forums.domain.com, I prefer this way personally. Then just put the files into the root folder where the subdomain points. Hope this helps.