Microsoft and Apple have already stopped supporting the older versions of Windows and OS X respectively.
As of April 2016, Google Chrome for Desktop will stop supporting Windows XP and Vista, along with OS X 10.6, 10.7 and 10.8. Google mentioned in its blog post that Microsoft and Apple have already stopped supporting the old versions of their operating systems.
The browser will continue working on these platforms, but it won’t receive any update or security patches after the given time, which may expose the system to malware, adware and viruses attack.
“If you are still on one of these unsupported platforms, we encourage you to move to a newer operating system to ensure that you continue to receive the latest Chrome versions and features” Google stated in an official blog post.
Earlier this year, Google announced that it will continue supporting the older versions until the end of 2015, mainly because these older operating systems still had a huge market share at that time.