There is no account associated with your forums account.
Go to https://x10hosting.com/control/ and login with forums username and password. Then go to http://x10hosting.com/signup.php and register a new hosting account.
Read this http://www.siteground.com/tutorials/wordpress/wordpress_manual_installation.htm and install wordpress manually. I will contact admins to fix the issue with Softaculous.
It looks like this is a temporary error, Cancel your signup attempt and then request hosting account again by going to http://x10hosting.com/signup.php