I have windows 8.1, IE 11 on a laptop and desktop. Cannot view Xfinity TV shows on either using IE. I downloaded Chrome Browser and used it to access Xfinity and everything works perfect on both computers. It appears Microsoft's integration of flash player into IE has created a problem that has caused many people a lot of wasted time.
I have other computers with Vista and Win7 and Xfinity works fine with them.