I'm working locally via WAMP install, doing various testing etc, am using phpbb3 on a live site.
Why do I need to have a working install directory of phpbb3 to perform the conversion? I backed and copied the DB to my local machine. Shouldn't you be able to convert your users and forums from the database only?
If not, can someone explain why its needed to this newbie? ::)
You don't need the entire phpbb3 installation.
However, you do need the database (SMF converter connects to the database, does not read a backup file, so you need to import the backup into a database).
And, you need a config file, a phpbb3-like config file, the converter checks for it and reads it, with the strictly necessary information: how to find that database. :)
I'm sorry I am on the run, but: you can find in this forum (phpbb subforum, or Converting to SMF forum) other topics telling what the config file needed is and what format it should be written as.
Or, you can copy your own (live) phpbb3 config file, and download it on your local machine, in a directory reserved for phpbb3, "simulating" an installation. It's all that's needed, really. Edit it to point to the local database, and make sure to enter the path to the "installation" when the converter asks you. :)