abacab: thanks again so much, yes I go into the BIOS via F2 at startup (F2 and F12 are my only options, F12 is supposed to take me into one time boot according to the manual but it doesn't) and my only options for Boot Option Priorities in F2, the BIOS are:

Boot Option #1 Windows Boot Manager
Boot Option #2 Onboard NIC IPV4
Boot Option #3 Onboard NIC IPV6
 
I've tried all three with the DVD Macrium Rescue Disk inserted and they all bring me immediately right back into windows.
 
I don't know what NIC IPV4 & 6 are, but they have a DVD and Flash drive icon next to them in Advanced Startup in windows (a link under Settings). If I go in thru this link (as opposed to the BIOS), I get the same options as above and they all restart immediately back into windows.
 
Incidentally, my total time online during this week of activity is about 15 minutes. Enough time for Microsoft to demand I download the updates (1803). Yesterday I got a BSOD upon startup after leaving sleep mode so I am not in a good position now.
 
I sincerely appreciate your and everyone's help but I am not sure I can crack this cookie open and I may have hosed my pc (essentially brand new, barely used, maybe 40 hours) by trying to create a rescue disk and allowing Microsoft in the backdoor.
 
Your help has been a super help over the years, you are a great guy!

haydn12
Do you have your flash drive inserted when booting?   If it was setup for UEFI boot, then it should appear as a UEFI Flash Boot device.     You may need to setup legacy mode to boot from a flash drive or DVD.  After image is restored, change the BIOS back to UEFI.  This is hard to explain as there are a few settings that have to be changed in the BIOS to get this to work and I don't have a Dell computer in front of me.
 
Jim 

Jim
 
No I made a rescue boot via DVD. There is apparently no option to boot into a DVD or flash drive via either F2 (Bios) or F12 (some list of things).
 
Sounds like good advice but I do not recall seeing anything about legacy in either F2 or F12.
 
Thanks so much though and I'll look into it further if my pc is not hosed, which it may be.

haydn12
Do you have your flash drive inserted when booting?   If it was setup for UEFI boot, then it should appear as a UEFI Flash Boot device.     You may need to setup legacy mode to boot from a flash drive or DVD.  After image is restored, change the BIOS back to UEFI.  This is hard to explain as there are a few settings that have to be changed in the BIOS to get this to work and I don't have a Dell computer in front of me.
 
Jim 

Jim
 
No I made a rescue boot via DVD. There is apparently no option to boot into a DVD or flash drive via either F2 (Bios) or F12 (some list of things).
 
Sounds like good advice but I do not recall seeing anything about legacy in either F2 or F12.
 
Thanks so much though and I'll look into it further if my pc is not hosed, which it may be.

There may be hope yet, I see in the dell forums there are many threads on cannot boot into a DVD on a Dell XPS 8920. I haven't read through them all but I think some have hinted at the solution in the above threads. I t may be I have to add the DVD as a boot option to do so I may have to disable secure boot and set UEFI as a boot option in the BIOS (F2) and then< once added, I can go into F12 and boot into DVD (Macrium rescue disk).
 
So there is hope if my pc is not dead.
 
Thanks again for ALL THE BIG help!