So I have a really complicated situation that I've put myself into. I have a 2013 iMac (September model) that has a painfully slow 5400 rpm hard drive. I had installed Windows 7 onto the Mac about 4 months ago and gotten the free upgrade to 10. Everything worked well. I bought a San Disk 240gb ssd to put in a USB enclosure and expected the Mac to detect it and be able to boot from it. I tried using multiple cloning programs to clone my windows install (that was ~48gb) to the 240gb ssd, and only one worked; others told me they couldn't align the partitions or something, i forget. When I tried to boot from the cloned drive, windows gave me INACCESSIBLE_BOOT_DEVICE. I assumed that the clone was bad, so I tried cloning again with no luck. I also tried refreshing to cloned install in windows recovery options with no luck. After that, I tried doing a Windows 7 install from a USB to see if it would boot from a fresh install. The windows install happily returned with "Can't install to USB Drive" or similar. For now, I've gone into the windows install on the hard drive and just moved server stuff onto the ssd, but I would really like to know if there is a way to boot off of the USB ssd. I think installing windows to the ssd when it is connected to my main computer with an actual SATA cable would help the windows install, but I don't know if that will make a difference when booting to it.