Google quietly announced Tuesday that Gmail will stop supporting older versions of its Chrome browser soon, in a move that will put another nail in the coffins of Windows XP and Windows Vista.Users of Chrome version 53 and older editions of the browser could start being redirected to the basic HTML version of Gmail as early as December, the company said in a blog post. Starting next week, users who will be affected by the change will start seeing a banner at the top of Gmail telling them to upgrade to an up-to-date version of Google\u2019s browser.The affected browser versions include Chrome v49, the last version of the software that supports XP and Vista. While Microsoft officially ended support for XP more than two and a half years ago, Gmail has continued to work with it. Vista Service Pack 2 will reach the end of its extended support period on April 11.Google also pointed out that users of outdated versions of Chrome are more vulnerable to security exploits, which is of particular importance for XP, because Microsoft is no longer even releasing security patches for the operating system.Google suggested that administrators managing Chrome on behalf of their users upgrade them at this point. If they can\u2019t be upgraded because of an incompatible OS, Google recommended admins take care of that as well.Windows XP still makes up 5 percent of the desktop browser market share worldwide, according to StatCounter\u2019s data from December 2016. That\u2019s a fraction of Windows 10\u2019s still-growing share of the pie — measured at 27.2 percent — but shows that there are still hold-outs.