NSIS

SIS stands for Nullsoft Scriptable Install System, a tool that allows software developers to create installers for their applications. The installation processes generated by NSIS contain all common options typically available in other, similar programs. One of the advantages of using NSIS is the ability to personalize the process to your liking. It has absolute flexibility in the different steps to show, tools to use, and even colors and formats. You'll have options powerful enough to create various alternative installations, uninstallers, and even detection of other installed versions. Fast, simple, and completely free.