oxygen_hl

That's not quite an accurate example... because wheels, etc., are installed as standard, but a laptop doesn't come off the assembly line with Vista pre-installed. That's already an upsell in the store. It's more appropriate to compare it to when they try to sell you additional equipment that you don't need, and in some cases, certain models already come with extras as standard (for example, models with more powerful engines almost always have more options than their less powerful counterparts), and you can't remove anything from them, regardless of your knowledge of the law, because it's a ready-made model.
But with Vista, etc., you just need to be confident and know your rights. When I bought a laptop, they not only sold it to me without any pre-installed software (although it originally had Vista), but they also downloaded the drivers for XP from the website and burned them to a CD in front of me (because now laptops only come with driver discs for Vista). Because the laws state that there should be full support, and if there is a version from the manufacturer (even from Windows 95/98), then everything should be included, and it used to be that way, but gradually it faded away.
And you need to consider all of this as a form of deception, not as a default setting.

P.S. Those who bought a computer and saw that Vista and XP cost the same... there was a price increase for licensed XP (to encourage people to buy Vista), and the prices were almost the same, even XP was more expensive. As is the case now (XP Home ~ $80, Prof ~ $150, and Vista Home Basic ~ $80, Home Premium ~ $120, Business ~ $150, Ultimate > $200).