Not Compatible with Internet Explorer anymore

I am using theme “Chocolat” by Mignon Style and it was working perfectly fine but few day back, everything went out of frame with Internet Explorer 10. I have searched a lot but couldn’t fine any solution that would work for me. Any suggestions. My website is zonizone.com
Second Question:
I want to created another menu on top bar, is it possible? If yes, how, where and what changes I need to do. (I am not programmer, just know basics of HTML).