Ok guys, im at wits end here. Got a 2011 MBP. Using cd drive caddy to hold extra HDD. I'm wanting to dual boot but have an OS on each drive not split like bootcamp wants to achieve. It's possible right? Surely. I for the life of me could not boot from external cd drive to run bootcamp install of win10 (restarts to boot from disk although just got black screen with blinking "_"). I did read that the external usb cd drive is no good to boot from, so the disk drive is returned to original internal and it will now boot into W10 installer although... Can't seem to get the right format happening for the HDD for windows installer to load it on. MBR / GPT / NFTS just win installer just can't do it. Surely it's just something stupid here. Tried third party apple disk utilities / os disk utility / windows installer drive utility. Anyone had similar issues using win installer to partition / format hdd for it's own install? Please note: bit of a noob here though.