Windows 8 product key not being accepted?

Heres how it goes down:

I boot from the usb and the Windows 8 logo appears. Then a purple screen pops up that asks for language preference and crap. I hit next and it takes me to a screen that says install. It also says repair computer in the bottom left. I hit install and it takes me to a page where I enter the product key. Thats the part I can't get past.

I called Microsoft and I tried everything they suggested but it still won't accept the key. What else can i do?