Today (24-2-2018) I downloaded and installed latest version on my windows 10 64 bit PC with only Office installed as application program (no other database systems etcetera....):

- Postgre SQL from https://www.postgresql.org/  (Kept all default settings in place).  Pgadmin4 is working.

- Downloaded latest Odoo 11 from https://www.odoo.com/nl_NL/page/download and installed odoo_11.0latest also with only the default settings.

At the end of the installation (After the Visual C res.) I get an error "the specified port number is not available. please select another" and then the installation continues automatically. 

When starting Odoo in Chrome (localhost:8069) I get an internal server error.

In my Windows firewall I added a rule for opening port 8069 and removed and installed Odoo again, but same error.  Odoo-server-11.0 is running and also postgresql-x64-10 is running (as I saw in the windows services).

Who might know how to solve this?