Actually, that F11 worked as said.
But the problem is still happening. Every now and then I get a white screen or an IE screen I just visited, that has no way to navigate out of it. Nothing shows in Applications in Task Manager. I've since noticed that in Processes 2 instances of iexplore.exe are running. When I End Task on both of them, the screen goes away.
Also, I removed Internet Explorer from my desktop so that I would be sure I'm not using it anymore. Firefox is my default browser, yet this is still happening. I now get that blank white screen every now and then.