Also the screenshot was taken after everything was working. When I originally set it, there was no 'Windows boot manager' and SCSI HD there. It seems UEFI let's OSes write to the BIOS or something.

I had the same problem yesterday. See my post, maybe it can help you:...

Hello Forum,

My Dell Precision T3600 originally came with Win7 x64 which I upgraded to Win10 successfully. However I wanted to do a fresh install of Win10 to get rid of accumulated OS mess that...