This is a question that comes up quite often by windows users, so thought we would share how we normally do it. The question is can you run a PostgreSQL server on your windows desktop/server box without having to install anything?
The answer is yes and quite easily. Why would you need to do this. There are a couple of cases -- one you are developing a single user app that you want users to be able to run from anywhere without having to install it first.
The other common reason is, you aren't allowed to install anything on a user's pc and you also want to package along a database you already have created.
For our purposes, many of our developers develop on portable WAMP like things, and for some of our applications, they need to work in both MySQL and PostgreSQL, so we need an easy way during development to swap one out for the other.