You cannot "import" raw PostgreSQL files directly into PokerTracker 4. You have to reinstall PostgreSQL using the same major version of PostgreSQL that was used originally for that install. So if PostgreSQL v9.3 was used for that you would have something like this:
C:\Program Files\PostgreSQL\9.3\data\
So in that case you would download and run the installer for PostgreSQL v9.3:
Download PostgreSQL