OEM downgrade rights for desktop PC operating systems apply to Windows Vista Business and Windows Vista Ultimate as stated in the License Terms. ' Can I downgrade my OEM version of Windows Vista Business to Windows XP Professional? This proved to be a boon because Microsoft offers a valid downgrade from Windows Vista Business / Ultimate Edition to Windows XP Professional. I paid a few extra bucks and went in for Vista Business rather than Home Edition. Because Vista sucks big time!! But there was one wise choice which I had made then unknowingly. The biggest blunder I believe I had done while purchasing my Llenovo Thinkpad T61 last year was to have it shipped with Vista rather than XP.
