Where can I delete/find the Postgre SQL that was aborted during installation?  

I installed the Odoo9.exe (All in One) but during its PostgreSQL, I aborted it.  When I tried again, it won't install the Postgre anymore.  and then when finished, the browser - localhost has http 500 error.  

Please help.  How can I troubleshoot this? We need to install with no demo data.

Thank you very much.