Resolved Autumn update stuck at installation - suggest Restart

Hi friends

I have done updates on 2 laptops from v1706 to 1709 using Window 10 update Assistant, no issues quite fast but ..

My last attempt on another Dell laptop, download ok, verified ok but at the updating (few expected restarts) it finally end with a message that machine could not complete installation, suggest restart installation.
To restart i have to press Esc or Enter to go into an endless Restart.

I have no way to do any other booting as the system is locked to continue installation.

Thus I am left with booting from a win v1706 .ISO to window RE. i tried all options in the repair but all fail to continue. There is only the command prompt left but i do not know how to roll back to the previous version using text commands. In the X: drive there are some .exe eg startrep but all get no where.

I am still hoping not to reinstall v1706.

Please advise & help. Thank you.

 

Update on my tinkering

In window RE environment, i go to command prompt option: from X: virtual drive i got to D: which is the original C: drive. Here i can see all the folders & files in the original C:
Then rename window.old to window after first renaming windows. Then I try to reboot it said that systen32/winbad.exe is missing. I am still trying to work around it; still hopeful.

Any views?

 

I have finally gave up & reinstall win 10 v1706.

However in this journey i learnt many new ways that were never in the older version of windows.

This link 7 ways to boot into Safe Mode in Windows 10 | Digital Citizen would be a good start to understand win 10 better to be able to tweat it.