Can I downgrade my OEM version of Windows 7 Professional to Windows Vista Business or Windows XP Professional?
Yes. OEM versions of Windows 7 Professional may be downgraded to either Windows Vista Business or Windows XP Professional. Similar end user downgrade rights are provided for the following Windows operating systems pre-installed on a new PC (OEM versions):
• Windows 7 Professional Edition
• Windows 7 Ultimate Edition
• Windows Vista Business Edition
• Windows Vista Ultimate Edition
Your ability to downgrade to a prior version of Windows is stated in the License Terms for these products. You can use the following media for your downgrade: Volume Licensing media (provided the end user has a Volume Licensing agreement), retail (FPP), or OEM (which includes system builder hologram CD, provided the software is acquired in accordance with the Microsoft OEM System Builder License). Use of the downgraded operating system is governed by the Windows 7 or Windows Vista License Terms for the original product pre-installed on the PC. You cannot use both the licensed Windows product and the downgrade product - only one Windows product can be used at a time. There are no downgrade rights granted for Windows 7 Starter, Windows 7 Home Basic, or Windows 7 Home Premium.