phpBB :: Knowledge base - Viewing article Transferring your MODded forum to a different host

If you have a MODded phpBB, that means you edited the files, and there also may have been SQL changes. If you want to move your present forums, in its exact state, to a different host, it's pretty easy.
You should first make sure you have the exact same phpBB files on your computer as the ones stored on your host. If you're not sure they are, download them to your computer via your favorite FTP client. Then, backup your phpBB forums if you haven't already. You can do this through the Administration Control Panel > Backup Database. Make sure you back up structure AND data.
Before you upload your phpBB files, you'll have to open the config.php in your favorite text editor, such as NotePad. Open it up, find all of the variable data fields, and change them to the values that apply to your new server. When you're finished save and close.
Now, you'll have to upload the phpBB files, the ones that you used at your old server, to your new one.
Before you start restoring your database, you should make sure your backup is less than 1MB or about. If it's more, it may be too large to upload at once, and you'll have to break it down into chunks. To do this, open up your *.sql backup file, and find anywhere with a ; (semi-color). You can choose to break up the file after this, create a new document, copy and paste. Now you have two chunks of files, both about or smaller than 1MB.
Once you're finished uploading the phpBB files, go into phpMyAdmin (or whatever your SQL management tool is) on your NEW host, and choose to "run a query from a textfile." Click on "browse" and find the *.sql backup file you've backed up. This backup file does not need to be uploaded to your site at all; it can be stored locally on your computer, as it probably is already. Click "GO" and wait for it to finish uploading. If all went well, you can go to your site and log in, and everything will be back to normal. Your MODs will remain intact, and the forum will still work as you backed up ALL of it.
You're done! Now, if you want to upgrade your forum, you'll have to follow one of the upgrade paths.