This is somewhat of a follow on to my earlier post dealing with migrating the OS to an SSD. After havinig cloned the OS from the 2TB HDD, I wanted to boot from the SSD. In the old days I would have gone to BIOS and from there selected boot priority of the various devices. In this instance, I encountered UEFI and could not figure out how to change boot priority. I saw options for legacy boot, some messages about disabling secure boot, and I was afraid to touch either. So....I just swapped the disk cables and booted from the SSD.
Still, I have the question, how can I change the boot priority? Is there some Dell manual that gives a good explanation of the UEFI interface for me to study?