Norton Internet Security antivirus update 'borked Internet Explorer'
Found on The Register on Saturday, 21 February 2015

Aggrieved users who'd thought far enough ahead to install Google Chrome, Mozilla Firefox or any of the other alternatives took to Norton's official forum to vent their spleens.
Tales of woe, heartbreak and downloads of new browsers spread, until about 0400 GMT, at which point a member of Symantec staff posted: "Kindly run manual live update (right click on Norton icon on tray notification area > 'Run live update ')," helpfully adding "Kindly stop using work-arounds.
People use Internet Explorer?
Norton does not test their software?