In this post I will explain how to run commands on windows EC2 instances during launch time only. While this is easily done on a Linux machine, the solution for windows is not as trivial. First we’ll present the Linux way and explain what we mean by “only during launch time”. Then, we’ll show 3 implementation attempts on windows, until we’ll reach the desired behavior. This post was written for programmers / devops professionals and assumes knowledge of EC2, launching instances and using user data.