http://oem.microsoft.com/script/contentpage.aspx?PageID=552836#desktop

Understanding Downgrade Rights
The Windows XP End-of-Sales presents a great opportunity for you to consult with your customers and grow your business. With higher levels of reliability, security, performance, administration, and support offered by Windows Vista with Service Pack 1, you can make a strong business case for Windows Vista.
When and Why Would Customers Use Downgrade Rights?
Example:
  • Your customer needs a new system running on the same platform as their existing systems – Windows XP Professional.
Solution: They can...
  • Purchase a PC with Windows Vista Business preinstalled
  • Downgrade – at no additional cost – to Windows XP Professional
  • When the time is right to move to Windows Vista Business, they are ready and licensed
Downgrade Rights for Windows Desktop Software

Downgrade rights are an end user right, documented in the License Terms that customers accept upon first running Windows software.

Customers must:
  • Purchase a PC preinstalled with Windows Vista
  • Accept the Windows Vista License Terms
  • Perform the downgrade or authorize an OEM to perform the downgrade
  • See additional details and FAQ
The Downgrade Process

Follow these steps to downgrade to a previous version of Windows:

  1. Obtain genuine Windows XP Professional or Tablet PC Edition media and a corresponding product key.
    • The media should come from a prior legally licensed version from the OEM, Retail, or Volume Licensing channels.
  2. Insert Windows XP Professional media in the CD drive and follow the installation instructions.
  3. Enter the product key
    • If previously activated, the software will be unable to activate online. In this case, the appropriate local Activation Support phone number will be displayed. Call the Activation Support Line and explain the circumstances. Once it is determined that the end user has a valid Windows Vista Business or Windows Vista Ultimate license, the Customer Service Representative will help them activate their software.
  4. Activate Windows XP software
  5. Also see the Step-by-Step Guide and FAQ for customers .pdf 930 KB
OEM Versions of Windows Eligible for Downgrade

Only certain OEM versions of Windows Vista include downgrade rights.

  • Windows Vista Business or Windows Vista Ultimate include downgrade rights to:
    • Windows XP Professional, or
    • Windows XP Tablet PC Edition, or
    • Windows XP Professional x64 Edition
Windows Vista downgrade path

Other OEM Windows Vista versions (for instance, Windows Vista Home versions) do not include downgrade rights.

Return to top

Downgrade Rights for Windows Server Software

Downgrade rights are an end user right, documented in the License Terms that customers accept upon first running Windows software.

Customers must:
  • Purchase a PC preinstalled with Windows Server 2008
  • Accept the Windows Server 2008 License Terms
  • Perform the downgrade or authorize an OEM to perform the downgrade
  • See additional details and FAQ
The Downgrade Process

Follow these steps to downgrade to a previous version of Windows server software:

  1. Obtain genuine Windows Server 2008 or Windows Small Business Server 2008 media and a corresponding product key.
    • The media should come from a prior legally licensed version from the OEM, Retail, or Volume Licensing channels.
  2. Insert the downgrade media in the CD drive and follow the installation instructions.
  3. Enter the product key
    • If previously activated, the software will be unable to activate online. In this case, the appropriate local Activation Support phone number will be displayed. Call the Activation Support Line and explain the circumstances. Once it is determined that the end user has a valid Windows Server license, the Customer Service Representative will help them activate their software.
  4. Activate the software
OEM Versions of Windows Server Eligible for Downgrade

Only certain OEM versions of Windows Server include downgrade rights. See below for the eligible versions.

  • Windows Server 2008 Standard includes downgrade rights to Windows Server 2003 Standard Edition
  • Windows Server 2008 Enterprise includes downgrade rights to Windows Server 2003 Enterprise Edition
  • Windows Small Business Server 2008 Premium includes downgrade rights to Windows Small Business Server 2003 Premium Edition or Windows Small Business Server 2003 R2.
Windows Server 2008 Standard downgrade path Windows Server 2008 Enterprise downgrade path Windows Small Business Server 2008 Primium downgrade path