New Future Build - Vista or XP - MS says both??

I'm currently collecting components for my first home build computer. As most of us, I'm struggling with which OS to purchase .... Vista or XP. My loyalty / comfort is with XP. But as time goes on, Vista may / could / should be the OS of choice. I ran across an interesting article at Information Week ... Ditching Vista: How To Downgrade To Windows XP. It would appear if you own Vista, MS will allow you to go back to a new legal version of XP on your Vista machine (Down grade or Side Install). The following is a snip from the article....

So if I understand this article, I can purchase Vista Ultimate Retail, install it. Then install XP (dual boot) and request / receive a legal activation at no cost. Not sure if one chooses to not dual boot and remove Vista and install XP / free activation ... if your original Vista activation stays active. It should, since MS could not monitor your computer as a dual boot or single boot system.

 

As you say, Vista will remain activated and still work, but Microsoft will know that your Vista no longer has a valid product key and so at the very least I would imagine all future Vista updates will be denied. It may even be possible to de-activate Vista the first time it phones home, but whether this is something MS would do I don’t know.