I want to back up my Windows system using System Image Backup (control panel - file history - system image backup).
Windows won't let me backup unless I include an external hard drive, and another internal hard drive, which makes the backup size prohibitive.
My C: drive is Windows that I want to back up.
My D: drive is another internal disk. That disk contains the EFI system partition. I used to be able to backup only the EFI system partition + Windows.
My P: drive has been used for File History once before, but File History is now turned off.
How do I tell Windows these drives are not system drives ?