After days trying get any form of windows install media to fresh install, all to no avail, I found the solution as I now looking at a fresh install. Why would these installation flash drives fail to install? I went with a paid flash media from MS. I built several from windows media creation tool. I tried MiniTool to create a gpt partition, even wiping the drive to zeros for a fresh. I had given up, ready to buy a new machine. But... By accident I removed the USB drive that was storing my Macrium backup sets. To my amazement windows setup ran to completion. This series of blundering around of three weeks, trying everything, getting nowhere was beat the ego out of someone who once bragged I could fix anything after being in the industry since 1983. New policy: set the workstation on the bench with only a keyboard, mouse and monitor. The setup process is obviously confused when external drives are plugged in. 
On a Windows update resulted in a "Preparing Automatic Repair". Every option in Automatic Repair got me nowhere. So, I restore Macrium Image 5 days old and got it back up. However any software installed that required a boot only gets me back to square one of Preparing Automatic Repair. Nothing I do will allow me to more forward. Tried installing from Windows Media Creation tool which fails at the "Next" button after first selecting partition to install to. I downloaded the Dell Recovery Tool. Selecting reset, the next window, both choices are "grey out". NO install tool will run to completion. I have run the Dell diagnostics tool with extended memory tests. All test pass. Then throwing gasoline on the problem, Dell Support told me that I was not going to be helped because the system was over 5 years old. Even with me paying for help? NO HELP POSSIBLE. It does not matter how long you have been a dedicated Dell owner. NO HELP! What I really would like to know, what are the UEFI BIOS setting for a T7910 PERC RAID5 system with 2 Processors, 2 CD drives. in desperation, I checked "restore default", when I didn't see how to select the boot devices I should see. Is it UEFI, Legacy, Secure boot? I have tried them all. If I choose ADD a device, I am shown a list of cryptic entries. Picking one to see what happens returns on file found. So, all I want from Dell is information how I should setup the BIOS. The documentation only explains some of the choices, not all.  So with Dells lack of help, paid or otherwise, my confusion on the BIOS setting, all I have here is an expensive "boat anchor". Such a shame to happen to a relative nice system that has some little glitch that fails to let me reinstall from scratch.  PS: As a side note, whenever I restore the Macrium Reflect image, the machine works perfect until the next boot. This must be some clue.
UEFI BIOS Setting for T7910