Internet Explorer 11 will be the only officially supported version of the browser for Windows 7, 8.1, and 10.
The only exception will be Windows Vista users, who will stick with Internet Explorer 9. Vista’s mainstream support ended more than a year before IE11 rolled out. The unpopular OS is almost up for retirement anyway. It reaches the end of its extended support phase in April 2017. After that, Vista will be unsupported just like Windows XP.
Anyone running a Windows 8.1 or Windows 10 system has nothing to worry about, as both of those systems came with IE11 preinstalled. Windows 7 users who don’t have automatic updates enabled, however, may not be running the latest version of IE. http://www.pcworld.com/article/3019538/windows/microsoft-officially-dumps-internet-explorer-8-9-and-10.html