Thanks for the reply. I did mean UEFI BIOS rather than UEFI settings. The Windows drive wouldn't show up in the boot order section. What I ended up doing was using an usb drive with Windows created from the Windows Media Creation Tool. I then just installed Windows over the older installation and it worked. So problem solved I say, and it goes without saying, but anyone doing what I did should back up their files. Maybe your way was better, though.