I am trying to install windows 7 on my mac book pro. I'm using a usb flash drive and an iso file. When I selected my iso, my usb, and my partition size, It restarted. But then I see a black screen with the sentence "no bootable device insert boot disk and press any key". This makes no sense because the flash drive is plugged in. But when I reboot and hold option, the windows partition is not there. The only thing there is my Mac os x partition. How do I fix this? I REALLY need to install windows. PLEASE HELP!!!