We have a customer that must use Internet Explorer for the work software. It is how the login, punch their time clocks, and perform sales. Well Internet Explorer suddenly stopped working.
The first time I uninstalled IE, and this worked for a short time. The real issue turned out to be EMET 5.0 was preventing it from running.
Solution was to uninstall EMET 5.0, download 5.1 and install it. Everything worked after that.
I hope this helps someone else.