it is set up to load a working copy based on your computers specs, if you have the latest of everything (and really in computer terms you never do), it might be worth while, as joe hinted, but if you have a perfectly good reasonable comp that's a few years old, your probably better to stick with xp
microsoft will pull it's usual trick of not supporting xp in the next year or so and then we'll all just have to buy.............mac's