My mother is like the guy you mentioned, and the rest of my family slightly less so (one of my brothers even plays the odd game or two.) I've never run Vista, but I did like Windows 7 (for general use) and Windows XP (for running old DOS games.) That being said, I found a program that works almost exactly like Paint (it's missing the "Paste From" command, although it'd be fine for making Paint chibis, sprites, or pixel art), although it costs $10 to get the full version (damn Mac trying to squeeze every penny out of me.)
No need to worry about me, my compy should be out of the shop soon and then things should be good. Also, no rush for the art; your well-being is much more important. I hope everything's going OK in your personal life now, and if I can help with that in any way all you need to do is ask.
Again, every decent argument I've heard in favor of using Macs is an argument of security or longevity. However, there's never anything about what costs those come at (in Macs' case, being much costlier and not being able to interact with 90% of programs. It's like deciding that to avoid being sick, you should never go outside.) The crappy arguments are basically "Macs are used by rich people and the cool kids, so you should too. You don't want to be a poor person or a loser, do you?" It's like an argument for a Ferrari or a Lamborghini (or some other fancy car), if the car in question didn't have a radio or AC.
The arguments that are against using Macs are more persuasive to me, especially since I've used a Mac at length now. With every moment I use this computer and find things that don't run on it, and differences that seem to have been made "just 'cause" the more I don't want it. Paint was just the straw that broke the camel's back. But again, I got it as a gift from my sister and she'd either be sad or angry if I asked to return this. It looks like my old compy can be fixed for cheap (warranty covers most of it), which probably means that once I get it back that the fancy gift Mac I'm using right now will be used as a spare, and only a spare.