I would suggest you reinstall and this time make sure the vb
license number has been entered in the config and on the 4th step you enter the cookie prefix of vb
which by default is bb.
You should be then able tologin fine.
If you dont want to reinstall you can edit your config-inc.php file and place the vblicense number and using phpmyadmin you can set settings 213-215 to the proper cookie settings to match vb