I just recently got a late 2013 27" refurb and I am trying to bootcamp it and having no luck. I get as far as the first windows 7 install splash screen where you choose the language but I have no USB mouse or keyboard. My USB mouse is lit up but nothing happens on the screen. I am using a legit USB2 key that I created using the Microsoft tool from a legit Windows 7 disc, why do I have no USB? I have tried every combination of the ports on the back, nothing works. I should also add that I am using a Dell USB keyboard and mouse, the keyboard works on the initial boot but is unresponsive once on the screen where I choose my language. Help?