Hello, I am trying to install a windows 10 preview bootcamp on my mid 2011 21.5" imac (I am aware of the danger of a preview OS). I made a boot disk, and followed the boot camp assistant. boot camp assistant downloads the drivers and installs them. Boot camp will not allow me to crete a boot disk from within itself. There are only 2 options, not 3. After that it askes me to install boot camp helper. After I correctly entered my password and hit add helper, I get screen that says "Install this Windows support after installing Windows. I can only hit quit from there.