Windows 10 obviously. After restart, about 65 IE windows opened up and screen blinking on and off and freezing up. I did a manual power down and same thing happened when it rebooted. I was able to eventually shut down all the IE windows. Only thing I've done so far is run malwarbytes and nothing popped up. I have not tried to restart again in fear it will do the same thing and as closing all those windows took a very long time.