Hey, Phill, thanks for warning me about the time it might take to get back to me...
Only really looking at the HDD atm due to the recent problem that you have had with it but fwiw the Dell driver installation order is here
What I would do, run the Windows AIO tool again (only the required tests) and run Seatools for Windows.
OK, I DL'd Framework, which has allowed me to run Seatools, except I don't know WHAT in Seatools I'm supposed to run. I no longer need it for HDD stability, and I don't see what in there could test/fix the Windows issue (i.e., that Windows update won't work).
I can DL and install this if you think it makes sense at this point:
https://www.microsof...ls.aspx?id=5582(in the past, when Windows automatically DLs this, as you likely know, it leads to other updates)
I can run that other repair tool from Tweaking.com once more if you think it could help in some way. (I doubt it at this point, but I do have Framework now if that makes any lick of difference.)
If possible, with your help, I can DL all of the drivers I need, put them on the desktop for easy access. REMOVE ALL of them (save for whatever I need to get into Windows Safe Mode), REINSTALL them in the order per the Dell website (which I would also need your help determining...).
I may try other things in the meantime, but I'll post if I do.