I don't mind helping, but Avery suggested FREE tools that work well for the job, paint3D is like trying to eat cereal with a fork, I mean it works, but it isn't the right tool for eating cereal. Graphicsgale is a free program as well as GIMP and learning resizing is considered a basic skill, I personally use it a lot.
I wanted to say that Avery's suggestion is what is best for you as a developer.