Google announced today that as of April 2016 Chrome will seize to support older platforms due to missing security updates. Platforms such as, Windows XP, Vista, and MAC OS 10.6, 10.7, 10.8 will no longer be supported by Google Chrome.
In today's announcement, Google encourages users of older platforms to update to a supported and a secure operating system. Google is taking this step, because such older platforms have a greater potential to be infected by malware and viruses.
Google Chrome will continue to operate on these platforms, but it has informed its users that they will no longer recieve any updates or security fixes. Starting April 2016 these updates and security fixes will not be available.
Even though Microsoft indends on still supporting Windows Vista until April 2017, Google Chrome will seize to support Vista operating systems before that date due to a non-substantial market share.
Google Chrome on Windows XP
Since April 2015 Google Chrome still supported Windows XP, even though a whole year had passed without receiving any security patches for over a year since the end of Microsoft's support on XP operating systems.
This made it difficult for Chrome to provide a secure environment for its users increasing the risk of XP users being infected by malware and viruses. Although the risk was high for XP users, Google had taken into consideration the millions of XP users, giving them an extention until the end of 2015.
In the meantime Google clarifies as to why they still supported Windows XP, even after Microsoft stopped supporting the operating system. Google explained that the reason behind that was the fact that Windows XP still had a substantial market share.
Source: Google