I have a H.P. DV6707US with vista installed and tried to install XP on it but the drivers are near impossible to find. And no, H.P. wont help since the unit came with Vista. Any suggestions?

So I have vista on now and have the upgradable xp disk, the one that you need a full version windows disk to upgrade with. Well any suggestions?
Can I use the vista disk to install the upgrade version of xp?

Before I had windows 7 home premium so I upgraded it to ultimate and a few days later it said that the windows 7 I had wasn’t genuine. And I still have the product key for windows 7 home premium. What should I do? Help! Also the product key that I used for windows 7 ultimate, I got it off the internet.

i currently have windows 7 home premium, and im thinking of upgrading to windows 7 ultimate. could some one please tell me how i would be able to downgrade to windows 7 home premium if i am not satisfied with windows 7 ultimate?