Please understand that we also do not have enough information about this thing. From the Downgrade Rights Chart, we can downgrade to Windows XP Professional and later to Windows Vista Business, however I cannot confirm if it will be changed.
For licensing questions, you can try to call 1-800-426-9400 (select option 4), Monday through Friday, 6:00 A.M. to 5:30 P.M. (PST) to speak directly to a Microsoft licensing specialist.
Worldwide customers can use the Guide to Worldwide Microsoft Licensing Sites http://www.microsoft.com/licensing/worldwide.aspx to find contact information in their locations.