You've made a nice program (on Windows) but it ain't over yet ! You need to package the program for your "customers" to be able to instal the program easily: that's when you need a good installer.
There are many installers programs on Windows: a nice list is available on Wikipedia (in English).
In 2006, I've used Nullsoft Scriptable Install System. At the time, I found it was the best solution matching my needs: copying a few files in a given directory and an Open Source solution.
Nowadays, even Microsoft has published an Open Source solution (WiX) ... we shall see !