Downloading PostGIS Install Packages and Binaries
Install packages or binary (precompiled) versions are available for a few different computing platforms.
PostgreSQL and PostGIS are both in active development, and some links and references for getting them installed can become quickly out of date. You should always refer to the main web sites for the latest pointers and instructions:
PostGIS for Windows
Native Windows versions of PostgreSQL have recently become available. These allow you to install the standard PostgreSQL database and, depending on the package, may also include PostGIS functionality. For packages that don't include all the PostGIS functionality, the PostGIS libraries and scripts need to be installed and run. Some Windows installation packages have been created to help automate this.
The official install package for PostgreSQL is available at ftp://ftp.postgresql.org/pub/binary/. Under the most recent version, there is a Windows folder.
One version was developed by Mark Cave-Ayland and is available from his web site , http://www.webbased.co.uk/mca/. He includes links to the main PostgreSQL installers as well as his own package containing PostGIS and other spatial libraries such as GEOS and Proj. This package is used by many people who frequent the PostGIS mailing list (which is the place to ask questions when you run into difficulty). See this link to search the archives of the mailing list or to subscribe to it: http://postgis.refractions.net/support.php.
PostGIS is ...