That means no new computers will be packaged with Windows 7 and 8.1 after the end of October 2016. Windows 8 will cease to be available as an original-equipment feature as early as June 2016, according to Microsoft's updates Windows life-cycle table.
After that, users who want to stick with an older version of Windows will have to manually install it.
The new cycle is a change from Microsoft's former policy of keeping all older systems up and running for at least two years after introducing a new system, reports ZDnet.com.
However, stopping the sales will not mean the end of technical support.
That means, Windows 7 will keep getting technical updates through January 2020, while Windows 8.1 will still get them through January 2023.