Fix Windows 10 blue screen

Factual Questions
1

Subsequent to a power-supply failure, a non-backed-up utility computer running (supposedly) Windows 10 Pro initially seemed to be OK [passed a CHKDSK and booted normally], but after [unclear precisely what happened] the Recovery Automatic Startup Repair later self-destructed it to a blue screen where it fails to boot, halting with an error that the registry in c:\windows\system32\config\system is corrupt. The files seem to be there and readable. Startup Repair does nothing.

Assuming it is verified that the RAM and disk are OK, is it possible to, well, easily fix it without installing a new OS? At least get a decent diagnostic error message?

PS it was not I who had the bright idea to install MS Windows on a workstation. Please do not flame me…

2

Can you boot into safe mode ?

If so, try running sfc/scannow from a command prompt.
You could also try dism /online /cleanup-image /scanhealth
and dism /online /cleanup-image /restorehealth

If not, create/borrow a bootable usb drive and run them from there.

You should also be able to restore to a previous restore point if that doesn’t
work.

3

Nope. At least, not that I can work out. Is there a secret way to do it?

Certainly I can boot Windows from a USB drive. However, those commands then don’t work, or seem to do much at all. In particular, I am not trying to clean up the /Online image, it would be at C:\Windows.

4

It depends on pc make/model. You should be able to google it.

For DISM from usb, i should’ve said to use the image option, ie;
dism /image:C:\ /cleanup-image /scanhealth
dism /image:C:\ /cleanup-image /restorehealth

5

Immediately exits with an Error 1009: An initialization error occured, and so does not actually check or repair any files. Is it even possible to do so without an image from somewhere of that exact release or update of Windows 10?

6

Hmm. I don’t know. Might be time to try a dedicated recovery utility.
iirc, i used lazesoft windows recovery last time i had a boot problem.

7

One problem with the whole situation is that, at least it seems to me, the error messages are not terribly informative. It says that such-and-such a registry file is corrupt, yet the file is readable, I can examine the entries in it and so on. If there were a way to determine what it thinks is corrupt, perhaps I could fix it.

8

Have you tried running a registry scanner like Ccleaner ?
It’s a long shot, but worth a try (it’s free !)

9

It turns out Tron sensibly backed up the registry, so I copied those files to the system directory and it booted.

I am still no wiser as far as how to actually repair a corrupted registry. I never received any specific error messages like that Key XYZ is invalid.