I rejected those answers, instead I chose something different, I chose the impossible, I chose...... Linux.... where the software is free, where the people don't have to worry about viruses.
It would be hard to charge someone for software that runs on something that is free. Its like giving someone a boat and then saying "Now you have to buy the paddles".
I upgraded to Vista, them went back to XP because a program i needed to use didn't work in Vista. I had had problems with Vista and thought maybe downgrading to XP is really an upgrade but all it did was remind me that XP too has problems so i went back to Vista when I didn't need to use that program any more. So currently I'm a Vista person and quite lovin' it.
There's no excuse for how slow it runs either. It's XP plus a new theme, a few new features, lots of bugs, and approximately 10 GB. When it comes to Windows, XP all the way.
I'm running Vista and to be honest, It's working pretty well for me. The first installation I did of it (about 6 months ago) I had nothing but problems. I eventually formatted and reinstalled and for whatever reason, it's been nearly flawless since. There are a few, small quirky bugs, but nothing too major.
I don't use a wide variety of "specialized" software so pretty much everything I have is supported. I would recommend giving it a shot. Despite the problems some people have had, it does a lot of things well, especially if your machine can handle it. The visuals are nice (feels more 'alive' than XP) and it's definitely nice to try something different.