Windows 7 has been out for over 5 years now with its launch back in October 2009, however today is the day that mainstream support ends with only security patches being available from now on. Exchange Server 2010 will also be losing mainstream support today.
Windows 7 Professional became unavailable in retail boxes back in 2013, however remains the most popular operating system for business with over half of all computers that are connected to the web running it. Support will end completely in January 2020 however there is currently no indication as to when Windows 7 will no longer be available pre-installed to PCs.
Windows 8 and 8.1 will no longer receive mainstream support after January 2018 with support ending entirely in January 2023. Windows 10 will be the next operating system release which will replace the existing Windows 8.1. More details will be released about Windows 10 at an event next week.