Just a note, Macs don't have registries, but clicking "reset safari" will delete all caches, passwords, usernames, histories, etc, anything that is temp data used by the browser. In other browsers, just navigate to the preferences and from there, find the "clear now" button (for firefox) to clear temp data.
And Macs don't need to be maintained like Windows does, just use as you wish. And maybe rebooting to clear up any old files.