help in the initial configuration of postgreSQL9.6
Basically your pg_hba.conf files need to be updated to work properly. To find out the location of the conf file, look for the main postgresql.conf file which is typically in the /Data directory.  

Also check your postgresql.conf file to see what port # it is listening on, you might have setup a non default port.  Running a netstat -an would help you verify that it is currently listening.  If it is not ensure the service or app is running.

After you validate that and you edit the pg_hba.conf you should restart the service in Windows then test again locally.  If you're running IPv6 the 'open to all' notation would be ::0/0, that's a common implementation but a poor security practice.  I would recommend only testing with that, then once it works, lock it down to specific IPs since you know everything is up and running.

Try this on your conf file and try to connect locally.  If you're using IPV6 use IPV6 addresses in CIDR-ADDRESS:

# TYPE  DATABASE    USER        CIDR-ADDRESS          METHOD
local   all         all                               trust


Here is the documentation for PostgreSQL hba_conf. 

The most recent common issues I've seen were when the server or client were using IPv6 or it was a default install and a client was trying to connect from a different IP than the server.  Otherwise you conf file could be setup wrong.