I have a suspicion!!
Have you guys tried to change your computer software from Vista to XP?
There is no problem in changing from XP to Vista. However, when you change it the opposite way, your computer does not accept XP and your computer is going to be messed up!!
I think this is done on purpose!! So that you have to buy the new products that are necessary to run Vista properly. I think it is a trick and I believe that it will happen the same with the new window 7. There should be some law to ensure that our choice is protected.
* TRY IT AND TELL ME ABOUT IT =]