Unfortunately, you're going to have to reinstall. Note, however, that none of the forum information itself will be lost (be sure to select the option to NOT overwrite the tables when doing the SQL part of the setup - it should be selected by default). You will, however, have lost most of the things configured through the admin panel, so you'll probably want to run through the Setup options again once installed to make sure everything is okay.
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com
Jason Rhinelander
Gossamer Threads
jason@gossamer-threads.com