Here comes another wise move by Microsoft, the company announced that Windows XP will continue to be available via Windows 7 downgrade rights. When Windows 7 RTM’d, Microsoft stated that end-users could downgrade right Windows 7 Professional or Windows 7 Ultimate editions preinstalled on a new PC would allow a customer to downgrade to either Windows XP Professional or similar Windows Vista versions for 18 months, or until the availability of SP1, whichever came sooner.
However another announcement has been made just before Official Windows XP SP2 expiration. Now end-user can downgrade Windows 7 Professional or Windows 7 Ultimate editions preinstalled on a new PC to either Windows XP Professional or similar Windows Vista versions until 2020, until Windows 7 lifecycle is discontinued.
Brandon LeBlanc, Windows Team Blog says-
To support our customers “unprecedented move” to migrate their PC environment to Windows 7, we have decided to extend downgrade rights to Windows XP Professional beyond the previously planned end date at Windows 7 SP1. This will help maintain consistency for downgrade rights throughout the Windows 7 lifecycle. As a result, the OEM versions of Windows 7 Professional and Windows 7 Ultimate will continue to include downgrade rights to the similar versions of Windows Vista or Windows XP Professional.
As per current Windows lifecycle policy, the company allows retailers to sell the boxed version of the previous OS for up to a year after release of a new OS, and that OEMs can sell PCs with the previous OS pre-loaded for up to 2 years after, the launch date of the new OS. which clearly states that retailers will be able to sell the boxed version of Windows Vista until October 22, 2010, and OEMs will be able to sell PCs with Windows Vista preinstalled until October 22, 2011.
Source: Windows Team Blog