If you are needing to transfer an entire WordPress site (entire meaning EVERYTHING) than here is the plugin you need!
- Install it, activate it.
- Go and make a backup/transfer of your entire site
- Upload the 2 files it creates, installer.php and the backup zip file to your new site
- Go to your new site and run the installer.php script
I have ran this many time on moving a site from development to production, changing servers (including new domains) and it works 100% well. It will even, if you are changing domain, go thru and update all links and such.