Comment XNA Studio 3.1 (Score 1) 704
I would look into installing Visual Studio C# Express 2008 and XNA Studio 3.1. This is a completely free setup for a Windows environment that has some incredibly easy examples and walkthroughs.
http://creators.xna.com/en-US/
Your child can have their first 2D game up and running in a day. This will help build confidence and make them want to learn more on their own.