Microsoft has officially discontinued the sale of Windows 7 and Windows 8. As of October 31, 2014, some versions of Windows 7 and 8 will no longer able available for consumer purchase.
As of October 31st, Windows 7 Home Basic, Home Premium, and Ultimate will no longer be available for purchase, directly from a retailer. Also the aforementioned OS's will not be pre-installed on any computers that are being sold through OEM's. Windows 7 Professional and 8 will also no longer be available for retail purchase, but these OS's will still be able to be found on PC's being sold by OEM's.
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See also: Windows lifecycle fact sheet - Windows Help