I just upgraded from using PostgreSQL v9.3 to v9.5 .. I use the following script to install PostgreSQL 9.5 on Windows:

postgresql-9.5.4-1.exe --serviceaccount postgres --servicepassword DataBase1 --servicename PostgreSQL95 --prefix C:\Database\postgresql --datadir C:\Database\datadir\postgresql --mode unattended
When I execute this script, it runs the initdb, creates the DataDir (i.e. C:\Database\datadir\postgresql) , also creates the PostgreSQL95 service and starts it which was not the case with PostgreSQL 9.3 .
(I used the exact same script for PostgreSQL 9.3 and it does not run the initdb or create the PostgreSQL95 during installation. I had to explicitly do it using another script.)

I am not sure if this is something new to v9.5 But want to know if there is a way to skip the dbinit and DB Service from being created while installing PostgreSQL 9.5

PS: I do not want to use the --extract-only option.