Restore computer to functional use, Currently in endless boot loop.

My wife has had a Dell Vostro laptop for 3-4 years. About 2 years ago it decided it didn't want to boot. Wife bought a newer Dell laptop for her work. Now I have a use for the Vostro (model railroading). Thought the problem might be a hard drive problem, but eventually found how to get to Safe Mode via F12 on first screen, then following a trail of alternatives. System rebooted into Safe Mode and was usable in that mode. Hard drive seemed OK by chkdsk. Copied entire hard drive contents to external drive. Tried using Restore saving personal files. Would no longer boot into Safe Mode. Tried using Restore back to Windows 10 Pro as installed, no other files save. Then system entered a "boot loop" that I am unable to break out of. The drive light flickers throughout the boot loop. Here is the sequence of the loop:

i. Black screen
ii. “Dell”, “Vostro”, “Energy Star”, “F2 Setup”, “F12 Boot Options”, progress bar appear briefly
iii. Black screen
iv. Window symbol appears on black
v. Rolling dots appear, moving
vi. Window symbol disappears, rolling dots still moving
vii. Window symbol reappears, rolling dots frozen with “Welcome” text below it
viii. Rolling dots start to move
ix. ”Restarting” text replaces “Welcome” briefly
x. Black screen
xi. Computer restarts

This sequence will repeat for hours if I let it. If I turn the system off, then on, it starts with "i." above and enters the same sequence. Pressing F12 in step "ii" has no effect.

So, that's it. Any thoughts?

Thanks
-Ted

PS Since my whole family upgraded from Windows 7 Pro to Windows 10 Pro during Microsoft’s grace period, I have no Window 10 Pro CD, nor a record of the product key assigned to this machine. Sigh!

Use Windows 10 Media Creation Tool to create yourself a Windows 10 installation media.


Please boot your computer with Windows Installation Media and from Windows Recovery Environment try to system restore Windows 10.


If you open the log file, you’ll be shown details of all the tests performed by Startup Repair, with any errors discovered detailed. We can use this information to help diagnose and get to the root cause of the problem.



To open log file from the Windows Recovery Environment, click and open the Command Prompt. When the Command Prompt is open, type Notepad and press Enter key to open the Notepad application. The Startup Repair log file is located at:

Code:

C:\Windows\System32\Logfiles\Srt\SrtTrail.txt

You will need to navigate to the drive on which you have Windows installed (usually the C: drive) to see the SrtTrail.txt log file.

Sometimes you can fix boot problems by creating a Macrium Reflect boot USB drive on a working PC, then boot the non working PC using that Reflect USB drive and choose the option fix boot problems.

Often boot problems may be fixed by turning off fast boot in Windows and the BIOS