If you have selected to install PostgreSQL then once PostgreSQL has been installed it will install PostGIS.
- Click I Agree to continue with the installation.
- Check the components as above and click Next.
Click Browse if you wish to change the Destination Folder and click Next.
If the Next button is not enabled then this is usually because the PostGIS installer has the slashes in the Destination Folder the wrong way around. Either manually change them or click Browse... and browse to the installation folder for PostgreSQL.
- Enter the following and click Next:
User Name: postgres
Password: enter the password that you gave the postgres user when you installed PostgreSQL.
Port: 5432
- Leave postgis as the Database Name and click Install.
- Click Yes.
- Click Close to continue with the Astun 3rd Party installation.