Can I upgrade my Windows XP–based computer to Windows 7 with the necessary disk configuration for BitLocker?
Upgrading from Windows XP to Windows 7 is not supported. For information about how to migrate your files and folders to Windows 7, see Step-by-Step: Windows 7 Upgrade and Migration (http://go.microsoft.com/fwlink/?LinkId=159582). After you install Windows 7 Ultimate or Windows 7 Enterprise, your computer disk configuration supports BitLocker by default.