Is validation supported for all versions of Windows?
Validation is a process that helps you to verify that your Microsoft® software is genuine and is supported for some versions of Windows®. Validation may be required for your copy of Windows prior to obtaining downloads and some updates from Microsoft (for example, the Microsoft Download Center Web site and Windows Update) reserved for PCs running genuine Windows Validation is also required in order for PCs running some Windows XP® editions to use the Windows Update Web site. All users can access security updates via Automatic Updates. Currently, online validation is supported for the following versions of Windows: Windows XP Home Edition, Windows XP Professional Edition (excluding Windows XP Professional x64 Edition), Windows XP Starter Edition, Windows XP Media Center Edition, and all editions of Windows Vista®.