I have been trying very hard to install win7 on my iMac with no success. I keep getting the "no bootable device" error. I have a mid-2011 imac with the latest Mavericks. I am using an aftermarket OWC SSD with 2TB HDD. I tried installing with a disc via the superdrive and an external drive. I have also tried from a USB flash drive. I created the flash drive using Boot Camp and windows. No success. Can someone please help.