This is most likely not a WP issue, but rather an issue with hostgator.
It looks like either their automated installer failed or there is a misconfiguration with the domain. Either way get in touch with them.
As a side note – I recommend doing a manual WP install instead of using an automated installer, if you’re able to. While automated installers usually work out fine, there are times when they’re configured to do things that are nice for the host but not really within best-practices for WP.
