Originally, downgrade rights — the sanctioned ability of Windows volume buyers to apply their new Windows licenses to older versions of the product — were due to expire around 2011 for Windows XP. But on July 12, the Softies gave XP yet another reprieve.

Users who purchase new PCs installed with Windows 7 Professional and Ultimate will now be able to downgrade to XP up until January 15, 2010 (for Windows 7 Professional) or January of 2020 (for Windows 7 Ultimate), according to Computerworld’s calculations.