Windows partition not showing up

I have succesfully created dualboot setup (Win10) on MacPro6,1 , iMac14,2, iMac 17,2 and iMac13,1.
Created a 2nd partition (FAT) with Disk Utility
With gdisk changed the disk to “protected” (instead of hybrid)
Boot de Mac from a SCCM bootstick en deployed a Task Sequence.
After that, the Windows partition shows up in Bootrunner and I can boot from it. So far so good.

The same is done on an iMac 16,2. Everything works fine except the part that at the end, the Windows partition doesn’t show up in Bootrunner. If booted with “alt” you can choose for Windows and boot from that partition. That part works fine. When booted in MacOS I can see in Disk Utility that the Windows partition isn’t mounted. Also it is not possible to mount the disk from Disk Utility.
The difference with all other models is that in Disk Utility the disks show up as “PCI” and on the 16,2iMac as “PCI Express”.

So which part do I miss here? What is going on here? I hope someone has a suggestion for this issue.


Boot Runner will automatically detected mounted volumes but you can also specify unmounted volumes.

See under the “Configuration Profile Keys” section.


Thanks for your reply.
I just tried this. The unmounted volumes is now showing in Bootrunner but without an icon. When selecting “Windows” to boot from, the iMac is rebooting. But it boots again in macOS.

Try disabling SIP and see if it boots correctly.