Friday 31st October 2014 sees End of Sales for certain flavours of the Windows client: Windows 8 will no longer be able through the Retail channel, and Windows 7 Home Basic, Home Premium, and Ultimate cease to be available pre-installed.

However, there are no End of Sales dates yet published for Windows 7 Professional or Windows 8 acquired through the OEM channel, which means that these products will be available for at least another year.

See the Windows Lifecycle Fact Sheet for all the dates: http://bit.ly/1FUEAsX.