kmeb,

Yes - you are right. I did post about trying to buy XP and then putting
Vista on later. The only proper way to do that is to do a fresh install by wiping the partition clean. Then you have to reinstall and reconfigure all of your programs and software. Not fun at all.

It is possible to do a dual-boot setup. Once it is correctly set up, theoretically it is easy to do. A potential drawback is that at some point, such a setup is very likely to get corrupted. It is not really a big deal - I had one that get doing that for a month until I figured out the cause. So, someone needs to be technically comfortable with such a setup because they will have to repair it when it breaks. Fixing is usually quick and easy, but some folks may not want to mess with it. Another drawback is disk maintenance, which now becomes more complicated.

I don't think this kind of setup makes much sense for most folks, with the exception of gamers and some folks who special software/hardware needs. Anyone buying a new machine now needs to know if they are in that category, but if they are not, then dual-booting XP and Vista, is a needless complexity that is anti-productivity. Now dual-booting Windows and Linux -- whole other story.