Hey guys, a friend and I installed a second hard drive into his 2011 Macbook Pro and now we're trying to install Windows 8.1 onto it with a bootable USB. We've tried using bootcamp, but for some reason the "Create Windows 7 or later install disk" option is not showing up. We took out the optical drive as well, so we can't use a CD. I've also tried making a boot usb on my PC, but the mac will not recognize it as a bootable device when starting up. Is there any other way we can accomplish this?