I started out making small incremental changes and testing but became frustrated with the lack of any sort of progress or meaningful -- at least to me -- results and then I broke the cardinal rule of troubleshooting -- change one thing at a time. I just completely changed all of the boot parameters to what I thought a clean UEFI setup would look like and, wa la, it booted and has run perfectly ever since. Hopefully the moderator will see this and delete the thread -- I can't see it being helpful to anyone.
I have two Maximus IX Hero mobos that were configured with the same hardware - I7-7700K cpu, BIOS 1301, 32GB (2x16GB) DDR4-3000 RAM and Seagate HDDs. They both booted and ran fine. Recently I got a good price on the new Intel SSDPEKNW020T8 NVMe PCI-e SSD. I plugged it in, used Casper 10 to make a bootable clone, told BIOS to boot from the new drive and wa la -- worked perfectly and runs like a bandit.
A couple weeks later Amazon had some really good pricing on the new WD Blue SN500 NVMe SSD and I bought one. Using the first PC's "twin" I then went through the same installation steps. While each step completes without error I have not been able to boot from it.
I can access it fine. Casper makes what appears to be a perfect clone and I can easily move files to/from it. It just won't function as a boot device. I get the blue screen abend with the "inaccessible boot device" error.
It looks to me like the BIOS for each machine is configured the same but there are so many parameters, many of them nested, that I wouldn't bet that they are all exactly the same.
Does anyone have any help for this?
Thanks in advance for whatever help you can offer.