I'm trying to install Windows 10 in BootCamp on my 2012 Macbook Pro, running mac OS Sierra, but fail to boot from the USB drive on which the Windows install tools reside. The error message I get is
No bootable device -- insert boot disk and press any key.
What I did so far:
- Tried to create a boot medium using Boot Camp assistant. This failed, because on the ISO-Image I have there is a file install.wim, which is too large for a FAT32-formatted drive.
- Tried to manually create the boot medium, using the above ISO-image, formatting the drive using ExFAT. This resulted in the above error message. I did some research and it seems that ExFAT is not bootable?
The most promising attempt was the following:
- So, since I have another device running Windows 10 available, I ended up installing Microsoft's MediaCreationTool and creating a FAT32-based bootable USB drive.
- Using this drive; I was once able to boot into the Windows 10 Installation. Since I was not able to quickly obtain a product key and thought I needed one for the installation, I canceled the installation at this point.
- After cancelling the installation, the Windows partition stopped showing up as a startup disk!
- I restarted the Boot Camp procedure, erasing- and re-creating the Bootcamp-partition.
- The USB drive stopped being recognised; I again get the above error message
No bootable device -- insert boot disk and press any key. In macOS the USB drive shows up without any problem.
I did a few more attempts (each time erasing and creating the bootcamp partition; trying to create another USB tool), but always with the same result.
Any help in getting this to run is appreciated. If possible, I'd like to avoid updating to mac OS Catalina.