petri[.]com/microsoft-issues-zero-day-advisory-for-internet-explorer
portal.msrc.microsoft[.]com/en-us/security-guidance/advisory/ADV200001
The newly discovered flaw affects Internet Explorer 9, 10, and 11 on Windows 7 through to Windows 10, and the respective Windows Server versions. The bug could be used to take complete control of a system and install new software, read and modify data, and create new accounts with full user rights. The bug is rated critical for Windows client SKUs...
While the flaw is being actively exploited in the wild, Microsoft says that so far that it is aware of limited targeted attacks.
Microsoft says that to exploit the flaw you would need to open a specially created web page, e.g. by clicking a link in an email. In win7 it would make sense to set another browser as default if you haven't already. IE 11 can be removed/uninstalled using Control Panel -> Add/remove Programs or Programs and Features [depending on Windows version], clicking the link on the upper left to turn features on/off. Doing so however will break many apps that use parts of Internet Explorer, so you'd need to check if anything you need is then broken, and decide if it was worth reinstalling [& updating] ie 11. Microsoft does provide a workaround [2nd link up top] that can help, but will reduce ie 11 functionality. It would also need to be reversed if/when Microsoft releases a fix.