If you have bought a wordpress hosting plan which is limited to single-site only then only one install will be shown. If it's cPanel hosting (shared web hosting) then you can have as many as WordPress installs. You can check the files through FTP protocol in your browser, or use open-source windows OS software WinSCP to log in with FTP and check the sub-folder where you have installed the second WordPress blog. If you find files, then check the wordpress configuration file and check for any wrong database password/database name inserted. Edit that file and correct it, save. If you still face problem, contact support rep who will check your database/wordpress install.