I think what youre looking for is something that has a simple enough interface for him to just putz around and play, but that has the underlying system capable of supporting a great deal of tinkering when the time comes. That said, I would avoid Windows. Although it is great for the average users that want to just get stuff done and dont care to tinker, and although it DOES actually provide a pretty decent amount of guts to play with, it has a tendency to dumb people down in the end. I think what you might be looking for, which I'm sure somebody mentioned, is something like Ubuntu. Simple easy to use interface for now, with a powerful back end for later, and he will learn a LOT more on this platform than any other. There are a decent amount of games and such for linux, and with a little help from daddy and WINE most windows games can be played as well. Not to mention that it is free. The hardware that you put this on is more or less irrelevant at this point, as most games for younger kids are not too intense, later down the line if he gets more into more complex gaming you can upgrade. If I could go back to when my son was that age, I would have done the same thing.